Commit Graph

3420 Commits

Author SHA1 Message Date
Nick Piggin 95c354fe9f spinlock: lockbreak cleanup
The break_lock data structure and code for spinlocks is quite nasty.
Not only does it double the size of a spinlock but it changes locking to
a potentially less optimal trylock.

Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a
__raw_spin_is_contended that uses the lock data itself to determine whether
there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is
not set.

Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to
decouple it from the spinlock implementation, and make it typesafe (rwlocks
do not have any need_lockbreak sites -- why do they even get bloated up
with that break_lock then?).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:20 +01:00
H. Peter Anvin 65ea5b0349 x86: rename the struct pt_regs members for 32/64-bit consistency
We have a lot of code which differs only by the naming of specific
members of structures that contain registers.  In order to enable
additional unifications, this patch drops the e- or r- size prefix
from the register names in struct pt_regs, and drops the x- prefixes
for segment registers on the 32-bit side.

This patch also performs the equivalent renames in some additional
places that might be candidates for unification in the future.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:56 +01:00
Roland McGrath 5b88abbf77 ptrace: generic PTRACE_SINGLEBLOCK
This makes ptrace_request handle PTRACE_SINGLEBLOCK along with
PTRACE_CONT et al.  The new generic code makes use of the
arch_has_block_step macro and generic entry points on machines
that define them.

[ mingo@elte.hu: bugfix ]

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:53 +01:00
Roland McGrath 36df29d799 ptrace: generic resume
This makes ptrace_request handle all the ptrace requests that wake
up the traced task.  These do low-level ptrace implementation magic
that is not arch-specific and should be kept out of arch code.  The
implementations on each arch usually do the same thing.  The new
generic code makes use of the arch_has_single_step macro and generic
entry points to handle PTRACE_SINGLESTEP.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Ingo Molnar 6e7c402590 x86: various changes and cleanups to in_p/out_p delay details
various changes to the in_p/out_p delay details:

- add the io_delay=none method
- make each method selectable from the kernel config
- simplify the delay code a bit by getting rid of an indirect function call
- add the /proc/sys/kernel/io_delay_type sysctl
- change 'io_delay=standard|alternate' to io_delay=0x80 and io_delay=0xed
- make the io delay config not depend on CONFIG_DEBUG_KERNEL

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: "David P. Reed" <dpreed@reed.com>
2008-01-30 13:30:05 +01:00
Venki Pallipadi 6378ddb592 time: track accurate idle time with tick_sched.idle_sleeptime
Current idle time in kstat is based on jiffies and is coarse grained.
tick_sched.idle_sleeptime is making some attempt to keep track of idle time
in a fine grained manner.  But, it is not handling the time spent in
interrupts fully.

Make tick_sched.idle_sleeptime accurate with respect to time spent on
handling interrupts and also add tick_sched.idle_lastupdate, which keeps
track of last time when idle_sleeptime was updated.

This statistics will be crucial for cpufreq-ondemand governor, which can
shed some conservative gaurd band that is uses today while setting the
frequency.  The ondemand changes that uses the exact idle time is coming
soon.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:04 +01:00
john stultz bbe4d18ac2 NTP: correct inconsistent ntp interval/tick_length usage
I recently noticed on one of my boxes that when synched with an NTP
server, the drift value reported for the system was ~283ppm. While in
some cases, clock hardware can be that bad, it struck me as unusual as
the system was using the acpi_pm clocksource, which is one of the more
trustworthy and accurate clocksources on x86 hardware.

I brought up another system and let it sync to the same NTP server, and
I noticed a similar 280some ppm drift.

In looking at the code, I found that the acpi_pm's constant frequency
was being computed correctly at boot-up, however once the system was up,
even without the ntp daemon running, the clocksource's frequency was
being modified by the clocksource_adjust() function.

Digging deeper, I realized that in the code that keeps track of how much
the clocksource is skewing from the ntp desired time, we were using
different lengths to establish how long an time interval was.

The clocksource was being setup with the following interval:
	NTP_INTERVAL_LENGTH = NSEC_PER_SEC/NTP_INTERVAL_FREQ

While the ntp code was using the tick_length_base value:
	tick_length_base ~= (tick_usec * NSEC_PER_USEC * USER_HZ)
					/NTP_INTERVAL_FREQ

The subtle difference is:
	(tick_usec * NSEC_PER_USEC * USER_HZ) != NSEC_PER_SEC

This difference in calculation was causing the clocksource correction
code to apply a correction factor to the clocksource so the two
intervals were the same, however this results in the actual frequency of
the clocksource to be made incorrect. I believe this difference would
affect all clocksources, although to differing degrees depending on the
clocksource resolution.

The issue was introduced when my HZ free ntp patch landed in 2.6.21-rc1,
so my apologies for the mistake, and for not noticing it until now.

The following patch, corrects the clocksource's initialization code so
it uses the same interval length as the code in ntp.c. After applying
this patch, the drift value for the same system went from ~283ppm to
only 2.635ppm.

I believe this patch to be good, however it does affect all arches and
I've only tested on x86, so some caution is advised. I do think it would
be a likely candidate for a stable 2.6.24.x release.

Any thoughts or feedback would be appreciated.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:03 +01:00
Ingo Molnar 45fe4fe191 x86: make clockevents more robust
detect zero event-device multiplicators - they then cause
division-by-zero crashes if a clockevent has been initialized
incorrectly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:03 +01:00
Thomas Gleixner 4713e22ce8 clocksource: add unregister function to disable unusable clocksources
On x86 the PIT might become an unusable clocksource. Add an unregister
function to provide a possibilty to remove the PIT from the list of
available clock sources.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:02 +01:00
Andi Kleen 1ada5cba6a clocksource: make clocksource watchdog cycle through online CPUs
This way it checks if the clocks are synchronized between CPUs too.
This might be able to detect slowly drifting TSCs which only
go wrong over longer time.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:02 +01:00
Parag Warudkar 1077f5a917 clocksource.c: use init_timer_deferrable for clocksource_watchdog
clocksource_watchdog can use a deferrable timer - reduces wakeups from
idle per second.

Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:01 +01:00
Geert Uytterhoeven efd9ac8630 time: fold __get_realtime_clock_ts() into getnstimeofday()
- getnstimeofday() was just a wrapper around __get_realtime_clock_ts()
  - Replace calls to __get_realtime_clock_ts() by calls to getnstimeofday()
  - Fix bogus reference to get_realtime_clock_ts(), which never existed

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:01 +01:00
Thomas Gleixner 186e3cb8a4 timer: clean up tick-broadcast.c
clean up tick-broadcast.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:01 +01:00
Pavel Machek b10db7f0d2 time: more timer related cleanups
I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
fixes. When there's copyright, there should be GPL.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:00 +01:00
Pavel Machek 4c9dc64122 time: timer cleanups
Small cleanups to tick-related code. Wrong preempt count is followed
by BUG(), so it is hardly KERN_WARNING.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:00 +01:00
Pavel Machek a6fa8e5a61 time: clean hungarian notation from timers
Clean up hungarian notation from timer code.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:00 +01:00
Linus Torvalds 0ba6c33bcd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25: (1470 commits)
  [IPV6] ADDRLABEL: Fix double free on label deletion.
  [PPP]: Sparse warning fixes.
  [IPV4] fib_trie: remove unneeded NULL check
  [IPV4] fib_trie: More whitespace cleanup.
  [NET_SCHED]: Use nla_policy for attribute validation in ematches
  [NET_SCHED]: Use nla_policy for attribute validation in actions
  [NET_SCHED]: Use nla_policy for attribute validation in classifiers
  [NET_SCHED]: Use nla_policy for attribute validation in packet schedulers
  [NET_SCHED]: sch_api: introduce constant for rate table size
  [NET_SCHED]: Use typeful attribute parsing helpers
  [NET_SCHED]: Use typeful attribute construction helpers
  [NET_SCHED]: Use NLA_PUT_STRING for string dumping
  [NET_SCHED]: Use nla_nest_start/nla_nest_end
  [NET_SCHED]: Propagate nla_parse return value
  [NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get
  [NET_SCHED]: act_api: use nlmsg_parse
  [NET_SCHED]: act_api: fix netlink API conversion bug
  [NET_SCHED]: sch_netem: use nla_parse_nested_compat
  [NET_SCHED]: sch_atm: fix format string warning
  [NETNS]: Add namespace for ICMP replying code.
  ...
2008-01-29 22:54:01 +11:00
Greg Kroah-Hartman 6494a93d55 Module: check to see if we have a built in module with the same name
When trying to load a module with the same name as a built-in one, a
scary kobject backtrace comes up.  Prevent that from checking for this
condition and warning the user as to what exactly is going on.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:27 +11:00
Jon Masters 0aa5bd52d0 module: add module taint on ndiswrapper
The struct module taints member is supposed to store per-module taint
data. The kernel knows about certain specific external modules that will
taint the kernel, such as ndiswrapper. Use of ndiswrapper possibly
should set the per-module taint in addition to the global kernel
taint flag, unless we're arguing not because wrapper module itself
is not what actually causes the kernel to be tainted as such?

Signed-off-by: Jon Masters <jcm@jonmasters.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:26 +11:00
Denis Cheng 8686c99875 module: fix the module name length in param_sysfs_builtin
the original code use KOBJ_NAME_LEN for built-in module name length,
that's defined to 20 in linux/kobject.h, but this is not enough appearntly,
many module names are longer than this;
 #define KOBJ_NAME_LEN                   20

another macro is MODULE_NAME_LEN defined in linux/module.h, I think this is
enough for module names:
 #define MODULE_NAME_LEN (64 - sizeof(unsigned long))

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:24 +11:00
Rusty Russell 6dd06c9fbe module: make module_address_lookup safe
module_address_lookup releases preemption then returns a pointer into
the module space.  The only user (kallsyms) copies the result, so just
do that under the preempt disable.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:23 +11:00
Rusty Russell bb9d3d56e7 module: better OOPS and lockdep coverage for loading modules
If we put the module in the linked list *before* calling into to, we
get the module name and functions in the OOPS (is_module_address can
find the module).  It also helps lockdep in a similar way.

Acked-and-tested-by: Joern Engel <joern@lazybastard.org>
Tested-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:22 +11:00
Rusty Russell efa5345e39 module: Fix gratuitous sprintf in module.c
Andrew sent an older version of this patch: we shouldn't use sprintf
to copy a string.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:21 +11:00
Rusty Russell c9a3ba55bb module: wait for dependent modules doing init.
There have been reports of modules failing to load because the modules
they depend on are still loading.  This changes the modules to wait
for a reasonable length of time in that case.  We time out eventually,
because there can be module loops or broken modules.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:20 +11:00
Rusty Russell a2da4052f1 module: Don't report discarded init pages as kernel text.
Current code could cause a bug in symbol_put_addr() if an arch used
kmalloc module text: we might think the symbol belongs to the core
kernel.

The downside is that this might make backtraces through (discarded)
init functions harder to read on some archs, but we already have that
issue for modules and noone has complained.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:18 +11:00
Pavel Emelyanov 08913681e4 [NET]: Remove the empty net_table
I have removed all the entries from this table (core_table,
ipv4_table and tr_table), so now we can safely drop it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:56:29 -08:00
Eric W. Biederman e51b6ba077 sysctl: Infrastructure for per namespace sysctls
This patch implements the basic infrastructure for per namespace sysctls.

A list of lists of sysctl headers is added, allowing each namespace to have
it's own list of sysctl headers.

Each list of sysctl headers has a lookup function to find the first
sysctl header in the list, allowing the lists to have a per namespace
instance.

register_sysct_root is added to tell sysctl.c about additional
lists of sysctl_headers.  As all of the users are expected to be in
kernel no unregister function is provided.

sysctl_head_next is updated to walk through the list of lists.

__register_sysctl_paths is added to add a new sysctl table on
a non-default sysctl list.

The only intrusive part of this patch is propagating the information
to decided which list of sysctls to use for sysctl_check_table.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman 23eb06de7d sysctl: Remember the ctl_table we passed to register_sysctl_paths
By doing this we allow users of register_sysctl_paths that build
and dynamically allocate their ctl_table to be simpler.  This allows
them to just remember the ctl_table_header returned from
register_sysctl_paths from which they can now find the
ctl_table array they need to free.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman 29e796fd4d sysctl: Add register_sysctl_paths function
There are a number of modules that register a sysctl table
somewhere deeply nested in the sysctl hierarchy, such as
fs/nfs, fs/xfs, dev/cdrom, etc.

They all specify several dummy ctl_tables for the path name.
This patch implements register_sysctl_path that takes
an additional path name, and makes up dummy sysctl nodes
for each component.

This patch was originally written by Olaf Kirch and
brought to my attention and reworked some by Olaf Hering.
I have changed a few additional things so the bugs are mine.

After converting all of the easy callers Olaf Hering observed
allyesconfig ARCH=i386, the patch reduces the final binary size by 9369 bytes.

.text +897
.data -7008

   text    data     bss     dec     hex filename
   26959310        4045899 4718592 35723801        2211a19 ../vmlinux-vanilla
   26960207        4038891 4718592 35717690        221023a ../O-allyesconfig/vmlinux

So this change is both a space savings and a code simplification.

CC: Olaf Kirch <okir@suse.de>
CC: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:16 -08:00
Jens Axboe fadad878cc kernel: add CLONE_IO to specifically request sharing of IO contexts
syslets (or other threads/processes that want io context sharing) can
set this to enforce sharing of io context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:36 +01:00
Jens Axboe d38ecf935f io context sharing: preliminary support
Detach task state from ioc, instead keep track of how many processes
are accessing the ioc.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:31 +01:00
Jens Axboe fd0928df98 ioprio: move io priority from task_struct to io_context
This is where it belongs and then it doesn't take up space for a
process that doesn't do IO.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:29 +01:00
Ingo Molnar 326e96b923 printk: revert ktime_get() timestamps
revert 19ef930927.

Kevin Winchester reported a lockup during X startup an bisected
it to this commit.

Reported-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-27 08:03:54 +01:00
Heiko Carstens 81ef16e763 [S390] Remove appldata include from sysctl_check.c
Forgot to remove this when removing the appldata binary sysctls.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26 14:11:16 +01:00
Linus Torvalds 9b73e76f3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits)
  [SCSI] usbstorage: use last_sector_bug flag universally
  [SCSI] libsas: abstract STP task status into a function
  [SCSI] ultrastor: clean up inline asm warnings
  [SCSI] aic7xxx: fix firmware build
  [SCSI] aacraid: fib context lock for management ioctls
  [SCSI] ch: remove forward declarations
  [SCSI] ch: fix device minor number management bug
  [SCSI] ch: handle class_device_create failure properly
  [SCSI] NCR5380: fix section mismatch
  [SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices
  [SCSI] IB/iSER: add logical unit reset support
  [SCSI] don't use __GFP_DMA for sense buffers if not required
  [SCSI] use dynamically allocated sense buffer
  [SCSI] scsi.h: add macro for enclosure bit of inquiry data
  [SCSI] sd: add fix for devices with last sector access problems
  [SCSI] fix pcmcia compile problem
  [SCSI] aacraid: add Voodoo Lite class of cards.
  [SCSI] aacraid: add new driver features flags
  [SCSI] qla2xxx: Update version number to 8.02.00-k7.
  [SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command.
  ...
2008-01-25 17:19:08 -08:00
Arjan van de Ven 6d082592b6 sched: keep total / count stats in addition to the max for
Right now, the linux kernel (with scheduler statistics enabled) keeps track
of the maximum time a process is waiting to be scheduled. While the maximum
is a very useful metric, tracking average and total is equally useful
(at least for latencytop) to figure out the accumulated effect of scheduler
delays. The accumulated effect is important to judge the performance impact
of scheduler tuning/behavior.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:35 +01:00
Peter Zijlstra 5973e5b954 sched: fix: don't take a mutex from interrupt context
print_cfs_stats is callable from interrupt context (sysrq), hence it should
not take mutexes. Change it to use RCU since the task group data is RCU
freed anyway.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Nick Piggin 5fb5e6de55 sched: print backtrace of running tasks too
The attached patch is something really simple that can sometimes help
in getting more info out of a hung system.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Ingo Molnar 19ef930927 printk: use ktime_get()
printk timestamps: use ktime_get().

Some platforms have a functioning clocksource function only after
they are done with early bootup, so delay this until out of
SYSTEM_BOOTING state.

it's also inherently safe now, as any bugs in this area will be
caught by the printk recursion checks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Ingo Molnar 90739081ef softlockup: fix signedness
fix softlockup tunables signedness.

mark tunables read-mostly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Arjan van de Ven 9745512ce7 sched: latencytop support
LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Dmitry Adamushko 326587b840 sched: fix goto retry in pick_next_task_rt()
looking at it one more time:

(1) it looks to me that there is no need to call
sched_rt_ratio_exceeded() from pick_next_rt_entity()

- [ for CONFIG_FAIR_GROUP_SCHED ] queues with rt_rq->rt_throttled are
not within this 'tree-like hierarchy' (or whatever we should call it
:-)

- there is also no need to re-check 'rt_rq->rt_time > ratio' at this
point as 'rt_rq->rt_time' couldn't have been increased since the last
call to update_curr_rt() (which obviously calls
sched_rt_ratio_esceeded())
well, it might be that 'ratio' for this rt_rq has been re-configured
(and the period over which this rt_rq was active has not yet been
finished)... but I don't think we should really take this into
account.

(2) now pick_next_rt_entity() must never return NULL, so let's change
pick_next_task_rt() accordingly.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Guillaume Chazarain cc203d2422 sched: monitor clock underflows in /proc/sched_debug
We monitor clock overflows, let's also monitor clock underflows.

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Guillaume Chazarain 782daeee3d sched: fix rq->clock warps on frequency changes
sched: fix rq->clock warps on frequency changes

Fix 2bacec8c31
(sched: touch softlockup watchdog after idling) that reintroduced warps
on frequency changes. touch_softlockup_watchdog() calls __update_rq_clock
that checks rq->clock for warps, so call it after adjusting rq->clock.

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Michal Schmidt 4f05b98d54 sched: fix, always create kernel threads with normal priority
Ensure that the kernel threads are created with the usual nice level
and affinity even if kthreadd's properties were changed from the
default by root.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Paolo Ciarrocchi 1ad82fd547 debug: clean up kernel/profile.c
Before:
 total: 25 errors, 13 warnings, 602 lines checked

 After:
 total: 0 errors, 2 warnings, 601 lines checked

No code changed:

kernel/profile.o:
   text    data     bss     dec     hex filename
   3048     236      24    3308     cec profile.o.before
   3048     236      24    3308     cec profile.o.after
 md5:
   2501d64748a4d350dffb11203e2a5182  profile.o.before.asm
   2501d64748a4d350dffb11203e2a5182  profile.o.after.asm

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Ingo Molnar 6478d8800b sched: remove the !PREEMPT_BKL code
remove the !PREEMPT_BKL code.

this removes 160 lines of legacy code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Ingo Molnar 58b8a73ab8 sched: make PREEMPT_BKL the default
make PREEMPT_BKL the default.

precursor to removal of the !PREEMPT_BKL code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Arjan van de Ven e14af7eeb4 debug: track and print last unloaded module in the oops trace
Based on a suggestion from Andi:

 In various cases, the unload of a module may leave some bad state around
 that causes a kernel crash AFTER a module is unloaded; and it's then hard
 to find which module caused that.

This patch tracks the last unloaded module, and prints this as part of the
module list in the oops trace.

Right now, only the last 1 module is tracked; I expect that this is enough
for the vast majority of cases where this information matters; if it turns
out that tracking more is important, we can always extend it to that.

[ mingo@elte.hu: build fix ]

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Arjan van de Ven 21aa9280b9 debug: show being-loaded/being-unloaded indicator for modules
It's rather common that an oops/WARN_ON/BUG happens during the load or
unload of a module. Unfortunatly, it's not always easy to see directly
which module is being loaded/unloaded from the oops itself. Worse,
it's not even always possible to ask the bug reporter, since there
are so many components (udev etc) that auto-load modules that there's
a good chance that even the reporter doesn't know which module this is.

This patch extends the existing "show if it's tainting" print code,
which is used as part of printing the modules in the oops/BUG/WARN_ON
to include a "+" for "being loaded" and a "-" for "being unloaded".

As a result this extension, the "taint_flags()" function gets renamed to
"module_flags()" (and takes a module struct as argument, not a taint
flags int).

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Peter Zijlstra 5a52dd5009 sched: rt-watchdog: fix .rlim_max = RLIM_INFINITY
Remove the curious logic to set it_sched_expires in the future. It useless
because rt.timeout wouldn't be incremented anyway.

Explicity check for RLIM_INFINITY as a test programm that had a 1s soft limit
and a inf hard limit would SIGKILL at 1s. This is because RLIM_INFINITY+d-1
is d-2.

Signed-off-by: Peter Zijlsta <a.p.zijlstra@chello.nl>
CC: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra 1020387f5f sched: rt-group: reduce rescheduling
Only reschedule if the new group has a higher prio task.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra 37bb6cb409 hrtimer: unlock hrtimer_wakeup
hrtimer_wakeup creates a

  base->lock
    rq->lock

lock dependancy. Avoid this by switching to HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
which doesn't hold base->lock.

This fully untangles hrtimer locks from the scheduler locks, and allows
hrtimer usage in the scheduler proper.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra d3d74453c3 hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback
Currently all highres=off timers are run from softirq context, but
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ timers expect to run from irq context.

Fix this up by splitting it similar to the highres=on case.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Peter Zijlstra 2d44ae4d71 hrtimer: clean up cpu->base locking tricks
In order to more easily allow for the scheduler to use timers, clean up
the locking a bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Peter Zijlstra 48d5e25821 sched: rt throttling vs no_hz
We need to teach no_hz about the rt throttling because its tick driven.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Mike Galbraith 614ee1f61f sched: pull_rt_task() cleanup
"goto out" is an odd way to spell "skip".

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:30 +01:00
Peter Zijlstra 6f505b1642 sched: rt group scheduling
Extend group scheduling to also cover the realtime classes. It uses the time
limiting introduced by the previous patch to allow multiple realtime groups.

The hard time limit is required to keep behaviour deterministic.

The algorithms used make the realtime scheduler O(tg), linear scaling wrt the
number of task groups. This is the worst case behaviour I can't seem to get out
of, the avg. case of the algorithms can be improved, I focused on correctness
and worst case.

[ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:30 +01:00
Peter Zijlstra fa85ae2418 sched: rt time limit
Very simple time limit on the realtime scheduling classes.
Allow the rq's realtime class to consume sched_rt_ratio of every
sched_rt_period slice. If the class exceeds this quota the fair class
will preempt the realtime class.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:29 +01:00
Peter Zijlstra 8f4d37ec07 sched: high-res preemption tick
Use HR-timers (when available) to deliver an accurate preemption tick.

The regular scheduler tick that runs at 1/HZ can be too coarse when nice
level are used. The fairness system will still keep the cpu utilisation 'fair'
by then delaying the task that got an excessive amount of CPU time but try to
minimize this by delivering preemption points spot-on.

The average frequency of this extra interrupt is sched_latency / nr_latency.
Which need not be higher than 1/HZ, its just that the distribution within the
sched_latency period is important.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:29 +01:00
Herbert Xu 02b67cc3ba sched: do not do cond_resched() when CONFIG_PREEMPT
Why do we even have cond_resched when real preemption
is on? It seems to be a waste of space and time.

remove cond_resched with CONFIG_PREEMPT on.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:28 +01:00
Ingo Molnar 03319ec8b0 sched: documentation, whitespace fixes
whitespace fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:28 +01:00
Peter Zijlstra 78f2c7db60 sched: SCHED_FIFO/SCHED_RR watchdog timer
Introduce a new rlimit that allows the user to set a runtime timeout on
real-time tasks their slice. Once this limit is exceeded the task will receive
SIGXCPU.

So it measures runtime since the last sleep.

Input and ideas by Thomas Gleixner and Lennart Poettering.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Lennart Poettering <mzxreary@0pointer.de>
CC: Michael Kerrisk <mtk.manpages@googlemail.com>
CC: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:27 +01:00
Peter Zijlstra fa717060f1 sched: sched_rt_entity
Move the task_struct members specific to rt scheduling together.
A future optimization could be to put sched_entity and sched_rt_entity
into a union.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:27 +01:00
Pavel Emelyanov 8eb703e4f3 uids: merge multiple error paths in alloc_uid() into one
There are already 4 error paths in alloc_uid() that do incremental rollbacks.
I think it's time to merge them.  This costs us 8 lines of code :)

Maybe it would be better to merge this patch with the previous one, but I
remember that some time ago I sent a similar patch (fixing the error path and
cleaning it), but I was told to make two patches in such cases.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:26 +01:00
Gregory Haskins dc938520d2 sched: dynamically update the root-domain span/online maps
The baseline code statically builds the span maps when the domain is formed.
Previous attempts at dynamically updating the maps caused a suspend-to-ram
regression, which should now be fixed.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:26 +01:00
Paul E. McKenney eaf649e9fe Preempt-RCU: CPU Hotplug handling
This patch allows preemptible RCU to tolerate CPU-hotplug operations.
It accomplishes this by maintaining a local copy of a map of online
CPUs, which it accesses under its own lock.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:25 +01:00
Paul E. McKenney e260be673a Preempt-RCU: implementation
This patch implements a new version of RCU which allows its read-side
critical sections to be preempted. It uses a set of counter pairs
to keep track of the read-side critical sections and flips them
when all tasks exit read-side critical section. The details
of this implementation can be found in this paper -

	http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf

and the article-

	http://lwn.net/Articles/253651/

This patch was developed as a part of the -rt kernel development and
meant to provide better latencies when read-side critical sections of
RCU don't disable preemption.  As a consequence of keeping track of RCU
readers, the readers have a slight overhead (optimizations in the paper).
This implementation co-exists with the "classic" RCU implementations
and can be switched to at compiler.

Also includes RCU tracing summarized in debugfs.

[ akpm@linux-foundation.org: build fixes on non-preempt architectures ]

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:24 +01:00
Paul E. McKenney e0ecfa7917 Preempt-RCU: fix rcu_barrier for preemptive environment.
Fix rcu_barrier() to work properly in preemptive kernel environment.
Also, the ordering of callback must be preserved while moving
callbacks to another CPU during CPU hotplug.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:24 +01:00
Paul E. McKenney 01c1c660f4 Preempt-RCU: reorganize RCU code into rcuclassic.c and rcupdate.c
This patch re-organizes the RCU code to enable multiple implementations
of RCU. Users of RCU continues to include rcupdate.h and the
RCU interfaces remain the same. This is in preparation for
subsequently merging the preemptible RCU implementation.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:24 +01:00
Dipankar Sarma c2d727aa2f Preempt-RCU: Use softirq instead of tasklets for
This patch makes RCU use softirq instead of tasklets.

It also adds a memory barrier after raising the softirq
inorder to ensure that the cpu sees the most recently updated
value of rcu->cur while processing callbacks.
The discussion of the related theoretical race pointed out
by James Huang can be found here --> http://lkml.org/lkml/2007/11/20/603

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:23 +01:00
Gregory Haskins c49443c538 sched: remove some old cpuset logic
We had support for overlapping cpuset based rto logic in early
prototypes that is no longer used, so remove it.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:23 +01:00
Gregory Haskins cdc8eb984c sched: RT-balance, only adjust overload state when changing
The overload set/clears were originally idempotent when this logic was first
implemented.  But that is no longer true due to the addition of the atomic
counter and this logic was never updated to work properly with that change.
So only adjust the overload state if it is actually changing to avoid
getting out of sync.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:23 +01:00
Steven Rostedt cb46984504 sched: RT-balance, add new methods to sched_class
Dmitry Adamushko found that the current implementation of the RT
balancing code left out changes to the sched_setscheduler and
rt_mutex_setprio.

This patch addresses this issue by adding methods to the schedule classes
to handle being switched out of (switched_from) and being switched into
(switched_to) a sched_class. Also a method for changing of priorities
is also added (prio_changed).

This patch also removes some duplicate logic between rt_mutex_setprio and
sched_setscheduler.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:22 +01:00
Steven Rostedt 9a897c5a67 sched: RT-balance, replace hooks with pre/post schedule and wakeup methods
To make the main sched.c code more agnostic to the schedule classes.
Instead of having specific hooks in the schedule code for the RT class
balancing. They are replaced with a pre_schedule, post_schedule
and task_wake_up methods. These methods may be used by any of the classes
but currently, only the sched_rt class implements them.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:22 +01:00
Peter Zijlstra 4bf0b77158 sched: remove do_div() from __sched_slice()
Yanmin Zhang noticed a nice optimization:

  p = l * nr / nl, nl = l/g -> p = g * nr

which eliminates a do_div() from __sched_period().

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:21 +01:00
Dmitry Adamushko 5d2f5a616d sched: get rid of 'new_cpu' in try_to_wake_up()
Clean-up try_to_wake_up().

Get rid of the 'new_cpu' variable in try_to_wake_up() [ that's, one
#ifdef section less ].  Also remove a few redundant blank lines.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:21 +01:00
Dmitry Adamushko 9ec3b77e11 sched: no need for 'affine wakeup' balancing
No need to do a check for 'affine wakeup and passive balancing possibilities'
in select_task_rq_fair() when task_cpu(p) == this_cpu.

I guess, this part got missed upon introduction of per-sched_class
select_task_rq() in try_to_wake_up().

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:21 +01:00
Ingo Molnar b913176917 sched: add credits for RT balancing improvements
add credits for RT balancing improvements.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:19 +01:00
Ingo Molnar 0eab914657 sched: style cleanup, #2
style cleanup of various changes that were done recently.

no code changed:

      text    data     bss     dec     hex filename
     26399    2578      48   29025    7161 sched.o.before
     26399    2578      48   29025    7161 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:19 +01:00
Ingo Molnar d7876a08db sched: remove unused JIFFIES_TO_NS() macro
remove unused JIFFIES_TO_NS() macro.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:19 +01:00
Ingo Molnar bdd7c81b49 sched: fix sched_rt.c:join/leave_domain
fix build bug in sched_rt.c:join/leave_domain and make them only
be included on SMP builds.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:18 +01:00
Gregory Haskins 637f50851b sched: only balance our RT tasks within our domain
We move the rt-overload data as the first global to per-domain
reclassification.  This limits the scope of overload related cache-line
bouncing to stay with a specified partition instead of affecting all
cpus in the system.

Finally, we limit the scope of find_lowest_cpu searches to the domain
instead of the entire system.  Note that we would always respect domain
boundaries even without this patch, but we first would scan potentially
all cpus before whittling the list down.  Now we can avoid looking at
RQs that are out of scope, again reducing cache-line hits.

Note: In some cases, task->cpus_allowed will effectively reduce our search
to within our domain.  However, I believe there are cases where the
cpus_allowed mask may be all ones and therefore we err on the side of
caution.  If it can be optimized later, so be it.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:18 +01:00
Gregory Haskins 57d885fea0 sched: add sched-domain roots
We add the notion of a root-domain which will be used later to rescope
global variables to per-domain variables.  Each exclusive cpuset
essentially defines an island domain by fully partitioning the member cpus
from any other cpuset.  However, we currently still maintain some
policy/state as global variables which transcend all cpusets.  Consider,
for instance, rt-overload state.

Whenever a new exclusive cpuset is created, we also create a new
root-domain object and move each cpu member to the root-domain's span.
By default the system creates a single root-domain with all cpus as
members (mimicking the global state we have today).

We add some plumbing for storing class specific data in our root-domain.
Whenever a RQ is switching root-domains (because of repartitioning) we
give each sched_class the opportunity to remove any state from its old
domain and add state to the new one.  This logic doesn't have any clients
yet but it will later in the series.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Christoph Lameter <clameter@sgi.com>
CC: Paul Jackson <pj@sgi.com>
CC: Simon Derr <simon.derr@bull.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:18 +01:00
Ingo Molnar 7f51f29820 sched: clean up schedule_balance_rt()
clean up schedule_balance_rt().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:17 +01:00
Ingo Molnar 80bf3171dc sched: clean up pull_rt_task()
clean up pull_rt_task().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:17 +01:00
Ingo Molnar 00597c3ed7 sched: remove leftover debugging
remove leftover debugging.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:16 +01:00
Ingo Molnar 6e1938d3ad sched: remove rt_overload()
remove rt_overload() - it's an unnecessary indirection.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:16 +01:00
Ingo Molnar 84de427489 sched: clean up kernel/sched_rt.c
clean up whitespace damage and missing comments in kernel/sched_rt.c.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:15 +01:00
Ingo Molnar deeeccd41b sched: clean up overlong line in kernel/sched_debug.c
clean up overlong line in kernel/sched_debug.c.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:15 +01:00
Ingo Molnar 4df64c0bfb sched: clean up find_lock_lowest_rq()
clean up find_lock_lowest_rq().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:15 +01:00
Ingo Molnar 79064fbf75 sched: clean up pick_next_highest_task_rt()
clean up pick_next_highest_task_rt().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:14 +01:00
Steven Rostedt 0d1311a536 sched: RT-balance on new task
rt-balance when creating new tasks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:14 +01:00
Steven Rostedt 610bf05645 sched: RT-balance, optimize cpu search
This patch removes several cpumask operations by keeping track
of the first of the CPUS that is of the lowest priority. When
the search for the lowest priority runqueue is completed, all
the bits up to the first CPU with the lowest priority runqueue
is cleared.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:13 +01:00
Gregory Haskins 06f90dbd76 sched: RT-balance, optimize
We can cheaply track the number of bits set in the cpumask for the lowest
priority CPUs.  Therefore, compute the mask's weight and use it to skip
the optimal domain search logic when there is only one CPU available.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:13 +01:00
Gregory Haskins 17b3279b48 sched: break out early if RT task cannot be migrated
We don't need to bother searching if the task cannot be migrated

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:13 +01:00
Steven Rostedt e1f47d891c sched: RT-balance, avoid overloading
This patch changes the searching for a run queue by a waking RT task
to try to pick another runqueue if the currently running task
is an RT task.

The reason is that RT tasks behave different than normal
tasks. Preempting a normal task to run a RT task to keep
its cache hot is fine, because the preempted non-RT task
may wait on that same runqueue to run again unless the
migration thread comes along and pulls it off.

RT tasks behave differently. If one is preempted, it makes
an active effort to continue to run. So by having a high
priority task preempt a lower priority RT task, that lower
RT task will then quickly try to run on another runqueue.
This will cause that lower RT task to replace its nice
hot cache (and TLB) with a completely cold one. This is
for the hope that the new high priority RT task will keep
 its cache hot.

Remeber that this high priority RT task was just woken up.
So it may likely have been sleeping for several milliseconds,
and will end up with a cold cache anyway. RT tasks run till
they voluntarily stop, or are preempted by a higher priority
task. This means that it is unlikely that the woken RT task
will have a hot cache to wake up to. So pushing off a lower
RT task is just killing its cache for no good reason.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:12 +01:00
Gregory Haskins a22d7fc187 sched: wake-balance fixes
We have logic to detect whether the system has migratable tasks, but we are
not using it when deciding whether to push tasks away.  So we add support
for considering this new information.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:12 +01:00
Gregory Haskins 6e1254d2c4 sched: optimize RT affinity
The current code base assumes a relatively flat CPU/core topology and will
route RT tasks to any CPU fairly equally.  In the real world, there are
various toplogies and affinities that govern where a task is best suited to
run with the smallest amount of overhead.  NUMA and multi-core CPUs are
prime examples of topologies that can impact cache performance.

Fortunately, linux is already structured to represent these topologies via
the sched_domains interface.  So we change our RT router to consult a
combination of topology and affinity policy to best place tasks during
migration.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:11 +01:00
Gregory Haskins 318e0893ce sched: pre-route RT tasks on wakeup
In the original patch series that Steven Rostedt and I worked on together,
we both took different approaches to low-priority wakeup path.  I utilized
"pre-routing" (push the task away to a less important RQ before activating)
approach, while Steve utilized a "post-routing" approach.  The advantage of
my approach is that you avoid the overhead of a wasted activate/deactivate
cycle and peripherally related burdens.  The advantage of Steve's method is
that it neatly solves an issue preventing a "pull" optimization from being
deployed.

In the end, we ended up deploying Steve's idea.  But it later dawned on me
that we could get the best of both worlds by deploying both ideas together,
albeit slightly modified.

The idea is simple:  Use a "light-weight" lookup for pre-routing, since we
only need to approximate a good home for the task.  And we also retain the
post-routing push logic to clean up any inaccuracies caused by a condition
of "priority mistargeting" caused by the lightweight lookup.  Most of the
time, the pre-routing should work and yield lower overhead.  In the cases
where it doesnt, the post-router will bat cleanup.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:10 +01:00
Gregory Haskins 2de0b4639f sched: RT balancing: include current CPU
It doesn't hurt if we allow the current CPU to be included in the
search.  We will just simply skip it later if the current CPU turns out
to be the lowest.

We will use this later in the series

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:10 +01:00
Gregory Haskins 07b4032c9e sched: break out search for RT tasks
Isolate the search logic into a function so that it can be used later
in places other than find_locked_lowest_rq().

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:10 +01:00
Gregory Haskins e7693a362e sched: de-SCHED_OTHER-ize the RT path
The current wake-up code path tries to determine if it can optimize the
wake-up to "this_cpu" by computing load calculations.  The problem is that
these calculations are only relevant to SCHED_OTHER tasks where load is king.
For RT tasks, priority is king.  So the load calculation is completely wasted
bandwidth.

Therefore, we create a new sched_class interface to help with
pre-wakeup routing decisions and move the load calculation as a function
of CFS task's class.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:09 +01:00
Gregory Haskins 697f0a487f sched: clean up this_rq use in kernel/sched_rt.c
"this_rq" is normally used to denote the RQ on the current cpu
(i.e. "cpu_rq(this_cpu)").  So clean up the usage of this_rq to be
more consistent with the rest of the code.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:09 +01:00
Gregory Haskins 73fe6aae84 sched: add RT-balance cpu-weight
Some RT tasks (particularly kthreads) are bound to one specific CPU.
It is fairly common for two or more bound tasks to get queued up at the
same time.  Consider, for instance, softirq_timer and softirq_sched.  A
timer goes off in an ISR which schedules softirq_thread to run at RT50.
Then the timer handler determines that it's time to smp-rebalance the
system so it schedules softirq_sched to run.  So we are in a situation
where we have two RT50 tasks queued, and the system will go into
rt-overload condition to request other CPUs for help.

This causes two problems in the current code:

1) If a high-priority bound task and a low-priority unbounded task queue
   up behind the running task, we will fail to ever relocate the unbounded
   task because we terminate the search on the first unmovable task.

2) We spend precious futile cycles in the fast-path trying to pull
   overloaded tasks over.  It is therefore optimial to strive to avoid the
   overhead all together if we can cheaply detect the condition before
   overload even occurs.

This patch tries to achieve this optimization by utilizing the hamming
weight of the task->cpus_allowed mask.  A weight of 1 indicates that
the task cannot be migrated.  We will then utilize this information to
skip non-migratable tasks and to eliminate uncessary rebalance attempts.

We introduce a per-rq variable to count the number of migratable tasks
that are currently running.  We only go into overload if we have more
than one rt task, AND at least one of them is migratable.

In addition, we introduce a per-task variable to cache the cpus_allowed
weight, since the hamming calculation is probably relatively expensive.
We only update the cached value when the mask is updated which should be
relatively infrequent, especially compared to scheduling frequency
in the fast path.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:07 +01:00
Steven Rostedt c7a1e46aa9 sched: disable standard balancer for RT tasks
Since we now take an active approach to load balancing, we don't need to
balance RT tasks via the normal task balancer. In fact, this code was
found to pull RT tasks away from CPUS that the active movement performed,
resulting in large latencies.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:07 +01:00
Steven Rostedt 4642dafdf9 sched: push RT tasks from overloaded CPUs
This patch adds pushing of overloaded RT tasks from a runqueue that is
having tasks (most likely RT tasks) added to the run queue.

TODO: We don't cover the case of waking of new RT tasks (yet).

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:07 +01:00
Steven Rostedt f65eda4f78 sched: pull RT tasks from overloaded runqueues
This patch adds the algorithm to pull tasks from RT overloaded runqueues.

When a pull RT is initiated, all overloaded runqueues are examined for
a RT task that is higher in prio than the highest prio task queued on the
target runqueue. If another runqueue holds a RT task that is of higher
prio than the highest prio task on the target runqueue is found it is pulled
to the target runqueue.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:07 +01:00
Steven Rostedt 4fd29176b7 sched: add rt-overload tracking
This patch adds an RT overload accounting system. When a runqueue has
more than one RT task queued, it is marked as overloaded. That is that it
is a candidate to have RT tasks pulled from it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:06 +01:00
Steven Rostedt e8fa136262 sched: add RT task pushing
This patch adds an algorithm to push extra RT tasks off a run queue to
other CPU runqueues.

When more than one RT task is added to a run queue, this algorithm takes
an assertive approach to push the RT tasks that are not running onto other
run queues that have lower priority.  The way this works is that the highest
RT task that is not running is looked at and we examine the runqueues on
the CPUS for that tasks affinity mask. We find the runqueue with the lowest
prio in the CPU affinity of the picked task, and if it is lower in prio than
the picked task, we push the task onto that CPU runqueue.

We continue pushing RT tasks off the current runqueue until we don't push any
more.  The algorithm stops when the next highest RT task can't preempt any
other processes on other CPUS.

TODO: The algorithm may stop when there are still RT tasks that can be
 migrated. Specifically, if the highest non running RT task CPU affinity
 is restricted to CPUs that are running higher priority tasks, there may
 be a lower priority task queued that has an affinity with a CPU that is
 running a lower priority task that it could be migrated to.  This
 patch set does not address this issue.

Note: checkpatch reveals two over 80 character instances. I'm not sure
 that breaking them up will help visually, so I left them as is.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:05 +01:00
Steven Rostedt 764a9d6fe4 sched: track highest prio task queued
This patch adds accounting to each runqueue to keep track of the
highest prio task queued on the run queue. We only care about
RT tasks, so if the run queue does not contain any active RT tasks
its priority will be considered MAX_RT_PRIO.

This information will be used for later patches.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:04 +01:00
Steven Rostedt 63489e45e2 sched: count # of queued RT tasks
This patch adds accounting to keep track of the number of RT tasks running
on a runqueue. This information will be used in later patches.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:03 +01:00
Ingo Molnar 82a1fcb902 softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks
this patch extends the soft-lockup detector to automatically
detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are
printed the following way:

 ------------------>
 INFO: task prctl:3042 blocked for more than 120 seconds.
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
 prctl         D fd5e3793     0  3042   2997
        f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 00000286
        f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 00000000
        f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 c0133a5b
 Call Trace:
  [<c04883a5>] schedule_timeout+0x6d/0x8b
  [<c04883d8>] schedule_timeout_uninterruptible+0x15/0x17
  [<c0133a76>] msleep+0x10/0x16
  [<c0138974>] sys_prctl+0x30/0x1e2
  [<c0104c52>] sysenter_past_esp+0x5f/0xa5
  =======================
 2 locks held by prctl/3042:
 #0:  (&sb->s_type->i_mutex_key#5){--..}, at: [<c0197d11>] do_fsync+0x38/0x7a
 #1:  (jbd_handle){--..}, at: [<c01ca3d2>] journal_start+0xc7/0xe9
 <------------------

the current default timeout is 120 seconds. Such messages are printed
up to 10 times per bootup. If the system has crashed already then the
messages are not printed.

if lockdep is enabled then all held locks are printed as well.

this feature is a natural extension to the softlockup-detector (kernel
locked up without scheduling) and to the NMI watchdog (kernel locked up
with IRQs disabled).

[ Gautham R Shenoy <ego@in.ibm.com>: CPU hotplug fixes. ]
[ Andrew Morton <akpm@linux-foundation.org>: build warning fix. ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-01-25 21:08:02 +01:00
Gautham R Shenoy 95402b3829 cpu-hotplug: replace per-subsystem mutexes with get_online_cpus()
This patch converts the known per-subsystem mutexes to get_online_cpus
put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and
CPU_LOCK_RELEASE hotplug notification events.

Signed-off-by: Gautham  R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:02 +01:00
Gautham R Shenoy 86ef5c9a8e cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()
Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use
get_online_cpus and put_online_cpus instead as it highlights the
refcount semantics in these operations.

The new API guarantees protection against the cpu-hotplug operation, but
it doesn't guarantee serialized access to any of the local data
structures. Hence the changes needs to be reviewed.

In case of pseries_add_processor/pseries_remove_processor, use
cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the
cpu_present_map there.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:02 +01:00
Gautham R Shenoy d221938c04 cpu-hotplug: refcount based cpu hotplug
This patch implements a Refcount + Waitqueue based model for
cpu-hotplug.

Now, a thread which wants to prevent cpu-hotplug, will bump up a global
refcount and the thread which wants to perform a cpu-hotplug operation
will block till the global refcount goes to zero.

The readers, if any, during an ongoing cpu-hotplug operation are blocked
until the cpu-hotplug operation is over.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Paul Jackson <pj@sgi.com> [For !CONFIG_HOTPLUG_CPU ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:01 +01:00
Srivatsa Vaddagiri 6b2d770026 sched: group scheduler, fix fairness of cpu bandwidth allocation for task groups
The current load balancing scheme isn't good enough for precise
group fairness.

For example: on a 8-cpu system, I created 3 groups as under:

	a = 8 tasks (cpu.shares = 1024)
	b = 4 tasks (cpu.shares = 1024)
	c = 3 tasks (cpu.shares = 1024)

a, b and c are task groups that have equal weight. We would expect each
of the groups to receive 33.33% of cpu bandwidth under a fair scheduler.

This is what I get with the latest scheduler git tree:

Signed-off-by: Ingo Molnar <mingo@elte.hu>
--------------------------------------------------------------------------------
Col1  | Col2    | Col3  |  Col4
------|---------|-------|-------------------------------------------------------
a     | 277.676 | 57.8% | 54.1%  54.1%  54.1%  54.2%  56.7%  62.2%  62.8% 64.5%
b     | 116.108 | 24.2% | 47.4%  48.1%  48.7%  49.3%
c     |  86.326 | 18.0% | 47.5%  47.9%  48.5%
--------------------------------------------------------------------------------

Explanation of o/p:

Col1 -> Group name
Col2 -> Cumulative execution time (in seconds) received by all tasks of that
	group in a 60sec window across 8 cpus
Col3 -> CPU bandwidth received by the group in the 60sec window, expressed in
        percentage. Col3 data is derived as:
		Col3 = 100 * Col2 / (NR_CPUS * 60)
Col4 -> CPU bandwidth received by each individual task of the group.
		Col4 = 100 * cpu_time_recd_by_task / 60

[I can share the test case that produces a similar o/p if reqd]

The deviation from desired group fairness is as below:

	a = +24.47%
	b = -9.13%
	c = -15.33%

which is quite high.

After the patch below is applied, here are the results:

--------------------------------------------------------------------------------
Col1  | Col2    | Col3  |  Col4
------|---------|-------|-------------------------------------------------------
a     | 163.112 | 34.0% | 33.2%  33.4%  33.5%  33.5%  33.7%  34.4%  34.8% 35.3%
b     | 156.220 | 32.5% | 63.3%  64.5%  66.1%  66.5%
c     | 160.653 | 33.5% | 85.8%  90.6%  91.4%
--------------------------------------------------------------------------------

Deviation from desired group fairness is as below:

	a = +0.67%
	b = -0.83%
	c = +0.17%

which is far better IMO. Most of other runs have yielded a deviation within
+-2% at the most, which is good.

Why do we see bad (group) fairness with current scheuler?
=========================================================

Currently cpu's weight is just the summation of individual task weights.
This can yield incorrect results. For ex: consider three groups as below
on a 2-cpu system:

	CPU0	CPU1
---------------------------
	A (10)  B(5)
		C(5)
---------------------------

Group A has 10 tasks, all on CPU0, Group B and C have 5 tasks each all
of which are on CPU1. Each task has the same weight (NICE_0_LOAD =
1024).

The current scheme would yield a cpu weight of 10240 (10*1024) for each cpu and
the load balancer will think both CPUs are perfectly balanced and won't
move around any tasks. This, however, would yield this bandwidth:

	A = 50%
	B = 25%
	C = 25%

which is not the desired result.

What's changing in the patch?
=============================

	- How cpu weights are calculated when CONFIF_FAIR_GROUP_SCHED is
	  defined (see below)
	- API Change
		- Two tunables introduced in sysfs (under SCHED_DEBUG) to
		  control the frequency at which the load balance monitor
		  thread runs.

The basic change made in this patch is how cpu weight (rq->load.weight) is
calculated. Its now calculated as the summation of group weights on a cpu,
rather than summation of task weights. Weight exerted by a group on a
cpu is dependent on the shares allocated to it and also the number of
tasks the group has on that cpu compared to the total number of
(runnable) tasks the group has in the system.

Let,
	W(K,i)  = Weight of group K on cpu i
	T(K,i)  = Task load present in group K's cfs_rq on cpu i
	T(K)    = Total task load of group K across various cpus
	S(K) 	= Shares allocated to group K
	NRCPUS	= Number of online cpus in the scheduler domain to
	 	  which group K is assigned.

Then,
	W(K,i) = S(K) * NRCPUS * T(K,i) / T(K)

A load balance monitor thread is created at bootup, which periodically
runs and adjusts group's weight on each cpu. To avoid its overhead, two
min/max tunables are introduced (under SCHED_DEBUG) to control the rate
at which it runs.

Fixes from: Peter Zijlstra <a.p.zijlstra@chello.nl>

- don't start the load_balance_monitor when there is only a single cpu.
- rename the kthread because its currently longer than TASK_COMM_LEN

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:00 +01:00
Srivatsa Vaddagiri a183561567 sched: introduce a mutex and corresponding API to serialize access to doms_curarray
doms_cur[] array represents various scheduling domains which are
mutually exclusive. Currently cpusets code can modify this array (by
calling partition_sched_domains()) as a result of user modifying
sched_load_balance flag for various cpusets.

This patch introduces a mutex and corresponding API (only when
CONFIG_FAIR_GROUP_SCHED is defined) which allows a reader to safely read
the doms_cur[] array w/o worrying abt concurrent modifications to the
array.

The fair group scheduler code (introduced in next patch of this series)
makes use of this mutex to walk thr' doms_cur[] array while rebalancing
shares of task groups across cpus.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:00 +01:00
Srivatsa Vaddagiri 58e2d4ca58 sched: group scheduling, change how cpu load is calculated
This patch changes how the cpu load exerted by fair_sched_class tasks
is calculated. Load exerted by fair_sched_class tasks on a cpu is now
a summation of the group weights, rather than summation of task weights.
Weight exerted by a group on a cpu is dependent on the shares allocated
to it.

This version of patch has a minor impact on code size, but should have
no runtime/functional impact for !CONFIG_FAIR_GROUP_SCHED.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:00 +01:00
Srivatsa Vaddagiri ec2c507fe8 sched: group scheduling, minor fixes
Minor bug fixes for the group scheduler:

- Use a mutex to serialize add/remove of task groups and also when
  changing shares of a task group. Use the same mutex when printing
  cfs_rq debugging stats for various task groups.

- Use list_for_each_entry_rcu in for_each_leaf_cfs_rq macro (when
  walking task group list)

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:07:59 +01:00
Srivatsa Vaddagiri 93f992ccc0 sched: group scheduling code cleanup
Minor cleanups:

- Fix coding style
- remove obsolete comment

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:07:59 +01:00
Ingo Molnar b842271fbb sched: remove printk_clock()
printk_clock() is obsolete - it has been replaced with cpu_clock().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:07:59 +01:00
Ingo Molnar d713f51933 sched: fix CONFIG_PRINT_TIME's reliance on sched_clock()
Stefano Brivio reported weird printk timestamp behavior during
CPU frequency changes:

  http://bugzilla.kernel.org/show_bug.cgi?id=9475

fix CONFIG_PRINT_TIME's reliance on sched_clock() and use cpu_clock()
instead.

Reported-and-bisected-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:07:58 +01:00
Ingo Molnar 32a7600668 printk: make printk more robust by not allowing recursion
make printk more robust by allowing recursion only if there's a crash
going on. Also add recursion detection.

I've tested it with an artificially injected printk recursion - instead
of a lockup or spontaneous reboot or other crash, the output was a well
controlled:

[   41.057335] SysRq : <2>BUG: recent printk recursion!
[   41.057335] loglevel0-8 reBoot Crashdump show-all-locks(D) tErm Full kIll saK showMem Nice powerOff showPc show-all-timers(Q) unRaw Sync showTasks Unmount shoW-blocked-tasks

also do all this printk-debug logic with irqs disabled.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Nick Piggin <npiggin@suse.de>
2008-01-25 21:07:58 +01:00
Linus Torvalds 7556afa0e0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
  [AVR32] extint: Set initial irq type to low level
  [AVR32] extint: change set_irq_type() handling
  [AVR32] NMI debugging
  [AVR32] constify function pointer tables
  [AVR32] ATNGW100: Update defconfig
  [AVR32] ATSTK1002: Update defconfig
  [AVR32] Kconfig: Choose daughterboard instead of CPU
  [AVR32] Add support for ATSTK1003 and ATSTK1004
  [AVR32] Clean up external DAC setup code
  [AVR32] ATSTK1000: Move gpio-leds setup to setup.c
  [AVR32] Add support for AT32AP7001 and AT32AP7002
  [AVR32] Provide more CPU information in /proc/cpuinfo and dmesg
  [AVR32] Oprofile support
  [AVR32] Include instrumentation menu
  Disable VGA text console for AVR32 architecture
  [AVR32] Enable debugging only when needed
  ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME
  [AVR32] Remove redundant try_to_freeze() call from do_signal()
  [AVR32] Drop GFP_COMP for DMA memory allocations
2008-01-25 08:40:02 -08:00
Haavard Skinnemoen 6ea6dd93c9 ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME
arch_ptrace_attach() is a hook that allows the architecture to do
book-keeping after a ptrace attach. This patch adds a call to this
hook when handling a PTRACE_TRACEME request as well.

Currently only one architecture, m32r, implements this hook. When
called, it initializes a number of debug trap slots in the ptraced
task's thread struct, and it looks to me like this is the right thing
to do after a PTRACE_TRACEME request as well, not only after
PTRACE_ATTACH. Please correct me if I'm wrong.

I want to use this hook on AVR32 to turn the debugging hardware on
when a process is actually being debugged and keep it off otherwise.
To be able to do this, I need to intercept PTRACE_TRACEME and
PTRACE_ATTACH, as well as PTRACE_DETACH and thread exit. The latter
two can be handled by existing hooks.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-01-25 08:31:39 +01:00
Kay Sievers af5ca3f4ec Driver core: change sysdev classes to use dynamic kobject names
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:40 -08:00
Greg Kroah-Hartman 78a2d906b4 Kobject: convert remaining kobject_unregister() to kobject_put()
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:40 -08:00
Greg Kroah-Hartman 7a6a41615b Modules: remove unneeded release function
Now that kobjects properly clean up their name structures, no matter if
they have a release function or not, we can drop this empty module
kobject release function too (it was needed prior to this because of the
way we handled static kobject names, we based the fact that if a release
function was present, then we could safely free the name string, now we
are more smart about things and only free names we have previously set.)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:39 -08:00
Greg Kroah-Hartman ac3c8141f6 Kobject: convert kernel/module.c to use kobject_init/add_ng()
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:38 -08:00
Kay Sievers 97c146ef07 sysfs: fix /sys/module/*/holders after sysfs logic change
Sysfs symlinks now require fully registered kobjects as a target,
otherwise the call to create a symlink will fail. Here we register
the kobject before we request the symlink in the holders directory.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Tejun Heo <teheo@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:36 -08:00
Greg Kroah-Hartman c63469a398 Driver core: move the driver specific module code into the driver core
The module driver specific code should belong in the driver core, not in
the kernel/ directory.  So move this code.  This is done in preparation
for some struct device_driver rework that should be confined to the
driver core code only.

This also lets us keep from exporting these functions, as no external
code should ever be calling it.

Thanks to Andrew Morton for the !CONFIG_MODULES fix.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:35 -08:00
Greg Kroah-Hartman cf15126b3d Kobject: convert kernel/user.c to use kobject_init/add_ng()
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:31 -08:00
Greg Kroah-Hartman e43b9192c5 Kobject: convert kernel/params.c to use kobject_init/add_ng()
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:31 -08:00
Greg Kroah-Hartman d76e15fb20 driver core: make /sys/power a kobject
/sys/power should not be a kset, that's overkill.  This patch renames it
to power_kset and fixes up all usages of it in the tree.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:25 -08:00
Greg Kroah-Hartman 0ff21e4663 kobject: convert kernel_kset to be a kobject
kernel_kset does not need to be a kset, but a much simpler kobject now
that we have kobj_attributes.

We also rename kernel_kset to kernel_kobj to catch all users of this
symbol with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:24 -08:00
Kay Sievers eb41d9465c fix struct user_info export's sysfs interaction
Clean up the use of ksets and kobjects. Kobjects are instances of
objects (like struct user_info), ksets are collections of objects of a
similar type (like the uids directory containing the user_info directories).
So, use kobjects for the user_info directories, and a kset for the "uids"
directory.

On object cleanup, the final kobject_put() was missing.

Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:18 -08:00
Kay Sievers 386f275f5d Driver Core: switch all dynamic ksets to kobj_sysfs_ops
Switch all dynamically created ksets, that export simple attributes,
to kobj_attribute from subsys_attribute. Struct subsys_attribute will
be removed.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:18 -08:00
Greg Kroah-Hartman 039a5dcd2f kset: convert /sys/power to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename power_subsys to power_kset to catch all users of the variable and
we properly export it so that people don't have to guess that it really
is present in the system.

The pseries code is wierd, why is it createing /sys/power if CONFIG_PM
is disabled?  Oh well, stupid big boxes ignoring config options...

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:16 -08:00
Greg Kroah-Hartman 7405c1e15e kset: convert /sys/module to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename module_subsys to module_kset to catch all users of the variable.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:16 -08:00
Greg Kroah-Hartman bd35b93d80 kset: convert kernel_subsys to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename kernel_subsys to kernel_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:14 -08:00
Greg Kroah-Hartman 4ff6abff83 kobject: get rid of kobject_add_dir
kobject_create_and_add is the same as kobject_add_dir, so drop
kobject_add_dir.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman 3514faca19 kobject: remove struct kobj_type from struct kset
We don't need a "default" ktype for a kset.  We should set this
explicitly every time for each kset.  This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:10 -08:00
Arjan van de Ven fabe874a48 lockdep: fix kernel crash on module unload
Michael Wu noticed in his lkml post at

    http://marc.info/?l=linux-kernel&m=119396182726091&w=2

that certain wireless drivers ended up having their name in module
memory, which would then crash the kernel on module unload.

The patch he proposed was a bit clumsy in that it increased the size of
a lockdep entry significantly; the patch below tries another approach,
it checks, on module teardown, if the name of a class is in module space
and then zaps the class.  This is very similar to what we already do
with keys that are in module space.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24 08:01:09 -08:00
Paul Mackerras 9156ad4833 Merge branch 'linux-2.6' 2008-01-24 10:07:21 +11:00
Paul Mackerras fa28237cfc [POWERPC] Provide a way to protect 4k subpages when using 64k pages
Using 64k pages on 64-bit PowerPC systems makes life difficult for
emulators that are trying to emulate an ISA, such as x86, which use a
smaller page size, since the emulator can no longer use the MMU and
the normal system calls for controlling page protections.  Of course,
the emulator can emulate the MMU by checking and possibly remapping
the address for each memory access in software, but that is pretty
slow.

This provides a facility for such programs to control the access
permissions on individual 4k sub-pages of 64k pages.  The idea is
that the emulator supplies an array of protection masks to apply to a
specified range of virtual addresses.  These masks are applied at the
level where hardware PTEs are inserted into the hardware page table
based on the Linux PTEs, so the Linux PTEs are not affected.  Note
that this new mechanism does not allow any access that would otherwise
be prohibited; it can only prohibit accesses that would otherwise be
allowed.  This new facility is only available on 64-bit PowerPC and
only when the kernel is configured for 64k pages.

The masks are supplied using a new subpage_prot system call, which
takes a starting virtual address and length, and a pointer to an array
of protection masks in memory.  The array has a 32-bit word per 64k
page to be protected; each 32-bit word consists of 16 2-bit fields,
for which 0 allows any access (that is otherwise allowed), 1 prevents
write accesses, and 2 or 3 prevent any access.

Implicit in this is that the regions of the address space that are
protected are switched to use 4k hardware pages rather than 64k
hardware pages (on machines with hardware 64k page support).  In fact
the whole process is switched to use 4k hardware pages when the
subpage_prot system call is used, but this could be improved in future
to switch only the affected segments.

The subpage protection bits are stored in a 3 level tree akin to the
page table tree.  The top level of this tree is stored in a structure
that is appended to the top level of the page table tree, i.e., the
pgd array.  Since it will often only be 32-bit addresses (below 4GB)
that are protected, the pointers to the first four bottom level pages
are also stored in this structure (each bottom level page contains the
protection bits for 1GB of address space), so the protection bits for
addresses below 4GB can be accessed with one fewer loads than those
for higher addresses.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-24 10:06:01 +11:00
James Bottomley d4acd722b7 [SCSI] sysfs: add filter function to groups
This patch allows the various users of attribute_groups to selectively
allow the appearance of group attributes.  The primary consumer of
this will be the transport classes in which we currently have
elaborate attribute selection algorithms to do this same thing.

Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-23 11:29:18 -06:00
Linus Torvalds b2214fca2b Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: group scheduler, set uid share fix
2008-01-22 09:18:45 -08:00
Randy Dunlap 00e10776ff rcu: fix section mismatch
rcu_online_cpu() should be __cpuinit instead of __devinit.

WARNING: vmlinux.o(.text+0x4b6d5): Section mismatch: reference to .init.text: (between 'rcu_cpu_notify' and 'wakeme_after_rcu')

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-22 09:17:48 -08:00
Ingo Molnar c61935fd0e sched: group scheduler, set uid share fix
setting cpu share to 1 causes hangs, as reported in:

    http://bugzilla.kernel.org/show_bug.cgi?id=9779

as the default share is 1024, the values of 0 and 1 can indeed
cause problems. Limit it to 2 or higher values.

These values can only be set by the root user - but still it
makes sense to protect against nonsensical values.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-22 11:24:58 +01:00
Randy Dunlap 48ccf3dac3 timer: fix section mismatch
The caller is __cpuinit.
Also, this code block and its caller are inside #ifdef CONFIG_HOTPLUG_CPU
blocks, so this code should reflect that config symbol's usage.

WARNING: vmlinux.o(.text+0x4252f): Section mismatch: reference to .init.text: (between 'timer_cpu_notify' and 'msleep')

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@akpm@linux-foundation.org>
2008-01-21 19:39:41 -08:00
Randy Dunlap 0ec160dd48 hrtimer: fix section mismatch
Fix section mismatch in hrtimer.c:

WARNING: vmlinux.o(.text+0x50c61): Section mismatch: reference to .init.text: (between 'hrtimer_cpu_notify' and 'down_read_trylock')

Noticed by Johannes Berg and confirmed by Sam Ravnborg.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@akpm@linux-foundation.org>
2008-01-21 19:39:41 -08:00
Nigel Cunningham 784680336b Fix unbalanced helper_lock in kernel/kmod.c
call_usermodehelper_exec() has an exit path that can leave the
helper_lock() call at the top of the routine unbalanced.  The attached
patch fixes this issue.

Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-17 15:38:59 -08:00
Johannes Berg eb13ba8738 lockdep: fix workqueue creation API lockdep interaction
Dave Young reported warnings from lockdep that the workqueue API
can sometimes try to register lockdep classes with the same key
but different names. This is not permitted in lockdep.

Unfortunately, I was unaware of that restriction when I wrote
the code to debug workqueue problems with lockdep and used the
workqueue name as the lockdep class name. This can obviously
lead to the problem if the workqueue name is dynamic.

This patch solves the problem by always using a constant name
for the workqueue's lockdep class, namely either the constant
name that was passed in or a string consisting of the variable
name.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-01-16 09:51:58 +01:00
Nick Piggin 5a26db5bd2 lockdep: fix internal double unlock during self-test
Lockdep, during self-test (when it was simulating double unlocks) was
sometimes unconditionally unlocking a spinlock when it had not been
locked. This won't work for ticket locks.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-01-16 09:51:58 +01:00
Rusty Russell cb2a52052c modules: de-mutex more symbol lookup paths in the module code
Kyle McMartin reports sysrq_timer_list_show() can hit the module mutex
from hard interrupt context.  These paths don't need to though, since we
long ago changed all the module list manipulation to occur via
stop_machine().

Disabling preemption is enough.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-14 08:52:22 -08:00
Linus Torvalds 417009f64f Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  pnpacpi: print resource shortage message only once
  PM: ACPI and APM must not be enabled at the same time
  ACPI: apply quirk_ich6_lpc_acpi to more ICH8 and ICH9
  ACPICA: fix acpi_serialize hang regression
  ACPI : Not register gsi for PCI IDE controller in legacy mode
  ACPI: Reintroduce run time configurable max_cstate for !CPU_IDLE case
  ACPI: Make sysfs interface in ACPI power optional.
  ACPI: EC: Enable boot EC before bus_scan
  increase PNP_MAX_PORT to 40 from 24
2008-01-13 09:58:22 -08:00
Roland McGrath 84427eaef1 remove task_ppid_nr_ns
task_ppid_nr_ns is called in three places.  One of these should never
have called it.  In the other two, using it broke the existing
semantics.  This was presumably accidental.  If the function had not
been there, it would have been much more obvious to the eye that those
patches were changing the behavior.  We don't need this function.

In task_state, the pid of the ptracer is not the ppid of the ptracer.

In do_task_stat, ppid is the tgid of the real_parent, not its pid.
I also moved the call outside of lock_task_sighand, since it doesn't
need it.

In sys_getppid, ppid is the tgid of the real_parent, not its pid.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-13 09:56:43 -08:00
Len Brown 02d5bccf8e Pull bugzilla-9194 into release branch 2008-01-11 12:27:13 -05:00
Len Brown 9f9adecd2d PM: ACPI and APM must not be enabled at the same time
ACPI and APM used "pm_active" to guarantee that
they would not be simultaneously active.

But pm_active was recently moved under CONFIG_PM_LEGACY,
so that without CONFIG_PM_LEGACY, pm_active became a NOP --
allowing ACPI and APM to both be simultaneously enabled.
This caused unpredictable results, including boot hangs.

Further, the code under CONFIG_PM_LEGACY is scheduled
for removal.

So replace pm_active with pm_flags.
pm_flags depends only on CONFIG_PM,
which is present for both CONFIG_APM and CONFIG_ACPI.

http://bugzilla.kernel.org/show_bug.cgi?id=9194

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2008-01-11 12:26:47 -05:00
Roland McGrath fcfd50afb6 show_task: real_parent
The show_task function invoked by sysrq-t et al displays the
pid and parent's pid of each task.  It seems more useful to
show the actual process hierarchy here than who is using
ptrace on each process.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-09 08:03:58 -08:00
Thomas Gleixner cdf71a10c7 futex: Prevent stale futex owner when interrupted/timeout
Roland Westrelin did a great analysis of a long standing thinko in the
return path of futex_lock_pi.

While we fixed the lock steal case long ago, which was easy to trigger,
we never had a test case which exposed this problem and stupidly never
thought about the reverse lock stealing scenario and the return to user
space with a stale state.

When a blocked tasks returns from rt_mutex_timed_locked without holding
the rt_mutex (due to a signal or timeout) and at the same time the task
holding the futex is releasing the futex and assigning the ownership of
the futex to the returning task, then it might happen that a third task
acquires the rt_mutex before the final rt_mutex_trylock() of the
returning task happens under the futex hash bucket lock. The returning
task returns to user space with ETIMEOUT or EINTR, but the user space
futex value is assigned to this task. The task which acquired the
rt_mutex fixes the user space futex value right after the hash bucket
lock has been released by the returning task, but for a short period of
time the user space value is wrong.

Detailed description is available at:

   https://bugzilla.redhat.com/show_bug.cgi?id=400541

The fix for this is the same as we do when the rt_mutex was acquired by
a higher priority task via lock stealing from the designated new owner.
In that case we already fix the user space value and the internal
pi_state up before we return. This mechanism can be used to fixup the
above corner case as well. When the returning task, which failed to
acquire the rt_mutex, notices that it is the designated owner of the
futex, then it fixes up the stale user space value and the pi_state,
before returning to user space. This happens with the futex hash bucket
lock held, so the task which acquired the rt_mutex is guaranteed to be
blocked on the hash bucket lock. We can access the rt_mutex owner, which
gives us the pid of the new owner, safely here as the owner is not able
to modify (release) it while waiting on the hash bucket lock.

Rename the "curr" argument of fixup_pi_state_owner() to "newowner" to
avoid confusion with current and add the check for the stale state into
the failure path of rt_mutex_trylock() in the return path of
unlock_futex_pi(). If the situation is detected use
fixup_pi_state_owner() to assign everything to the owner of the
rt_mutex.

Pointed-out-and-tested-by: Roland Westrelin <roland.westrelin@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-08 16:21:39 -08:00
Ken'ichi Ohmichi 83a08e7c6e vmcoreinfo: add the array length of "free_list" for filtering free pages
This patch adds the array length of "free_area.free_list" to the vmcoreinfo
data so that makedumpfile (dump filtering command) can exclude all free pages
in linux-2.6.24.

makedumpfile creates a small dumpfile by excluding unnecessary pages for the
analysis. To distinguish unnecessary pages, makedumpfile gets the vmcoreinfo
data which has the minimum debugging information only for dump filtering.

In 2.6.24-rc1 or later, the free_area.free_list is an array which has one list
for each migrate types instead of a single list. makedumpfile needs the array
length of "free_area.free_list" and the vmcoreinfo data should contain it.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Tested-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Acked-by: Simon Horman <horms@verge.net.au>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-08 16:10:36 -08:00
Roland McGrath b59f8197c5 acct: real_parent ppid
The ac_ppid field reported in process accounting records
should match what getppid() would have returned to that
process, regardless of whether a debugger is attached.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-07 14:55:37 -08:00
Linus Torvalds 39cd72de49 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: fix gcc warnings
2008-01-03 12:01:00 -08:00
Linus Torvalds b8c9a18712 Fix kernel/ptrace.c compile problem (missing "may_attach()")
The previous commit missed one use of "may_attach()" that had been
renamed to __ptrace_may_attach().  Tssk, tssk, Al.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-02 13:48:27 -08:00
Al Viro 831830b5a2 restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace pid
Contents of /proc/*/maps is sensitive and may become sensitive after
open() (e.g.  if target originally shares our ->mm and later does exec
on suid-root binary).

Check at read() (actually, ->start() of iterator) time that mm_struct
we'd grabbed and locked is
 - still the ->mm of target
 - equal to reader's ->mm or the target is ptracable by reader.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-02 13:13:27 -08:00
Ingo Molnar 90b2628f1f sched: fix gcc warnings
Meelis Roos reported these warnings on sparc64:

  CC      kernel/sched.o
  In file included from kernel/sched.c:879:
  kernel/sched_debug.c: In function 'nsec_high':
  kernel/sched_debug.c:38: warning: comparison of distinct pointer types lacks a cast

the debug check in do_div() is over-eager here, because the long long
is always positive in these places. Mark this by casting them to
unsigned long long.

no change in code output:

   text    data     bss     dec     hex filename
  51471    6582     376   58429    e43d sched.o.before
  51471    6582     376   58429    e43d sched.o.after

  md5:
   7f7729c111f185bf3ccea4d542abc049  sched.o.before.asm
   7f7729c111f185bf3ccea4d542abc049  sched.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-30 17:24:35 +01:00
David S. Miller fb445ee5f9 [SERIAL]: Fix section mismatches in Sun serial console drivers.
We're exporting an __init function, oops :-)

The core issue here is that add_preferred_console() is marked
as __init, this makes it impossible to invoke this thing from
a driver probe routine which is what the Sparc serial drivers
need to do.

There is no harm in dropping the __init marker.  This code will
actually work properly when invoked from a modular driver,
except that init will probably not pick up the console change
without some other support code.

Then we can drop the __init from sunserial_console_match()
and we're no longer exporting an __init function to modules.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-29 01:19:49 -08:00
Greg Kroah-Hartman d172f4ef31 Modules: fix memory leak of module names
Due to the change in kobject name handling, the module kobject needs to
have a null release function to ensure that the name it previously set
will be properly cleaned up.

All of this wierdness goes away in 2.6.25 with the rework of the kobject
name and cleanup logic, but this is required for 2.6.24.

Thanks to Alexey Dobriyan for finding the problem, and to Kay Sievers
for pointing out the simple way to fix it after I tried many complex
ways.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-12-22 23:09:05 -08:00
Arjan van de Ven 2c3b20e91f debug: add end-of-oops marker
Right now it's nearly impossible for parsers that collect kernel crashes
from logs or emails (such as www.kerneloops.org) to detect the
end-of-oops condition. In addition, it's not currently possible to
detect whether or not 2 oopses that look alike are actually the same
oops reported twice, or are truly two unique oopses.

This patch adds an end-of-oops marker, and makes the end marker include
a very simple 64-bit random ID to be able to detect duplicate reports.

Normally, this ID is calculated as a late_initcall() (in the hope that
at that time there is enough entropy to get a unique enough ID); however
for early oopses the oops_exit() function needs to generate the ID on
the fly.

We do this all at the _end_ of an oops printout, so this does not impact
our ability to get the most important portions of a crash out to the
console first.

[ Sidenote: the already existing oopses-since-bootup counter we print
  during crashes serves as the differentiator between multiple oopses
  that trigger during the same bootup. ]

Tested on 32-bit and 64-bit x86. Artificially injected very early
crashes as well, as expected they result in this constant ID after
multiple bootups:

  ---[ end trace ca143223eefdc828 ]---
  ---[ end trace ca143223eefdc828 ]---

because the random pools are still all zero. But it all still works
fine and causes no additional problems (which is the main goal of
instrumentation code).

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-20 15:01:17 +01:00
Peter Zijlstra 67e2be0232 sched: rt: account the cpu time during the tick
Realtime tasks would not account their runtime during ticks. Which would lead
to:

        struct sched_param param = { .sched_priority = 10 };
        pthread_setschedparam(pthread_self(), SCHED_FIFO, &param);

	while (1) ;

Not showing up in top.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-20 15:01:17 +01:00
Linus Torvalds 3e3b3916a9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: fix "Kernel panic - not syncing: IO-APIC + timer doesn't work!"
  genirq: revert lazy irq disable for simple irqs
  x86: also define AT_VECTOR_SIZE_ARCH
  x86: kprobes bugfix
  x86: jprobe bugfix
  timer: kernel/timer.c section fixes
  genirq: add unlocked version of set_irq_handler()
  clockevents: fix reprogramming decision in oneshot broadcast
  oprofile: op_model_athlon.c support for AMD family 10h barcelona performance counters
2007-12-18 09:42:44 -08:00
Steven Rostedt 971e5b35fb genirq: revert lazy irq disable for simple irqs
In commit 76d2160147 lazy irq disabling
was implemented, and the simple irq handler had a masking set to it.

Remy Bohmer discovered that some devices in the ARM architecture
would trigger the mask, but never unmask it. His patch to do the
unmasking was questioned by Russell King about masking simple irqs
to begin with. Looking further, it was discovered that the problems
Remy was seeing was due to improper use of the simple handler by
devices, and he later submitted patches to fix those. But the issue
that was uncovered was that the simple handler should never mask.

This patch reverts the masking in the simple handler.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-12-18 18:05:58 +01:00
Adrian Bunk b4be625852 timer: kernel/timer.c section fixes
This patch fixes the following section mismatches with CONFIG_HOTPLUG=n,
CONFIG_HOTPLUG_CPU=y:

...
WARNING: vmlinux.o(.text+0x41cd3): Section mismatch: reference to .init.data:tvec_base_done.22610 (between 'timer_cpu_notify' and 'run_timer_softirq')
WARNING: vmlinux.o(.text+0x41d67): Section mismatch: reference to .init.data:tvec_base_done.22610 (between 'timer_cpu_notify' and 'run_timer_softirq')
...

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-18 18:05:58 +01:00
Thomas Gleixner cdc6f27d9e clockevents: fix reprogramming decision in oneshot broadcast
Resolve the following regression of a choppy, almost unusable laptop:

 http://lkml.org/lkml/2007/12/7/299
 http://bugzilla.kernel.org/show_bug.cgi?id=9525

A previous version of the code did the reprogramming of the broadcast
device in the return from idle code. This was removed, but the logic in
tick_handle_oneshot_broadcast() was kept the same.

When a broadcast interrupt happens we signal the expiry to all CPUs
which have an expired event. If none of the CPUs has an expired event,
which can happen in dyntick mode, then we reprogram the broadcast
device. We do not reprogram otherwise, but this is only correct if all
CPUs, which are in the idle broadcast state have been woken up.

The code ignores, that there might be pending not yet expired events on
other CPUs, which are in the idle broadcast state. So the delivery of
those events can be delayed for quite a time.

Change the tick_handle_oneshot_broadcast() function to check for CPUs,
which are in broadcast state and are not woken up by the current event,
and enforce the rearming of the broadcast device for those CPUs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 18:05:58 +01:00
Ingo Molnar 6cbf1c126c sched: do not hurt SCHED_BATCH on wakeup
measurements by Yanmin Zhang have shown that SCHED_BATCH tasks benefit
if they run the same place_entity() logic as SCHED_OTHER tasks - so
uniformize behavior in this area.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 15:21:13 +01:00
Ingo Molnar 2bacec8c31 sched: touch softlockup watchdog after idling
touch softlockup watchdog after idling.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 15:21:13 +01:00
Eric Dumazet 73c4efd2c8 sched: sysctl, proc_dointvec_minmax() expects int values for
min_sched_granularity_ns, max_sched_granularity_ns,
min_wakeup_granularity_ns and max_wakeup_granularity_ns are declared
"unsigned long".

This is incorrect since proc_dointvec_minmax() expects plain "int" guard
values.

This bug only triggers on big endian 64 bit arches.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 15:21:13 +01:00
Livio Soares c7af77b584 sched: mark rwsem functions as __sched for wchan/profiling
This following commit

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fdf8cb0909b531f9ae8f9b9d7e4eb35ba3505f07

un-inlined a low-level rwsem function, but did not mark it as __sched.
The result is that it now shows up as thread wchan (which also affects
/proc/profile stats).  The following simple patch fixes this by properly
marking rwsem_down_failed_common() as a __sched function.

Also in this patch, which is up for discussion, marks down_read() and
down_write() proper as __sched.  For profiling, it is pretty much
useless to know that a semaphore is beig help - it is necessary to know
_which_ one.  By going up another frame on the stack, the information
becomes much more useful.

In summary, the below change to lib/rwsem.c should be applied; the
changes to kernel/rwsem.c could be applied if other kernel hackers agree
with my proposal that down_read()/down_write() in the profile is not
enough.

[ akpm@linux-foundation.org: build fix ]

Signed-off-by: Livio Soares <livio@eecg.toronto.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 15:21:13 +01:00
Dmitry Adamushko 051a1d1afa sched: fix crash on ia64, introduce task_current()
Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and
sched_move_task()) must handle a given task differently in case it's the
'rq->curr' task on its run-queue. The task_running() interface is not
suitable for determining such tasks for platforms with one of the
following options:

#define __ARCH_WANT_UNLOCKED_CTXSW
#define __ARCH_WANT_INTERRUPTS_ON_CTXSW

Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but
such a task is not necessarily 'rq->curr'.

The detailed explanation is available here:
https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 15:21:13 +01:00
Eric W. Biederman 64396accc2 sysctl: fix ax25 checks
Fix:

sysctl table check failed: /net/ax25/ax0/ax25_default_mode .3.9.1.2 Unknown
sysctl binary path
Pid: 2936, comm: kissattach Not tainted 2.6.24-rc5 #1
 [<c012ca6a>] set_fail+0x3b/0x43
 [<c012ce7a>] sysctl_check_table+0x408/0x456
 [<c012ce8e>] sysctl_check_table+0x41c/0x456
 [<c012ce8e>] sysctl_check_table+0x41c/0x456
 ...

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Bernard Pidoux <pidoux@ccr.jussieu.fr>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-17 19:28:17 -08:00
Nishanth Aravamudan 368d2c6358 Revert "hugetlb: Add hugetlb_dynamic_pool sysctl"
This reverts commit 54f9f80d65 ("hugetlb:
Add hugetlb_dynamic_pool sysctl")

Given the new sysctl nr_overcommit_hugepages, the boolean dynamic pool
sysctl is not needed, as its semantics can be expressed by 0 in the
overcommit sysctl (no dynamic pool) and non-0 in the overcommit sysctl
(pool enabled).

(Needed in 2.6.24 since it reverts a post-2.6.23 userspace-visible change)

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-17 19:28:17 -08:00
Nishanth Aravamudan d1c3fb1f8f hugetlb: introduce nr_overcommit_hugepages sysctl
hugetlb: introduce nr_overcommit_hugepages sysctl

While examining the code to support /proc/sys/vm/hugetlb_dynamic_pool, I
became convinced that having a boolean sysctl was insufficient:

1) To support per-node control of hugepages, I have previously submitted
patches to add a sysfs attribute related to nr_hugepages. However, with
a boolean global value and per-mount quota enforcement constraining the
dynamic pool, adding corresponding control of the dynamic pool on a
per-node basis seems inconsistent to me.

2) Administration of the hugetlb dynamic pool with multiple hugetlbfs
mount points is, arguably, more arduous than it needs to be. Each quota
would need to be set separately, and the sum would need to be monitored.

To ease the administration, and to help make the way for per-node
control of the static & dynamic hugepage pool, I added a separate
sysctl, nr_overcommit_hugepages. This value serves as a high watermark
for the overall hugepage pool, while nr_hugepages serves as a low
watermark. The boolean sysctl can then be removed, as the condition

	nr_overcommit_hugepages > 0

indicates the same administrative setting as

	hugetlb_dynamic_pool == 1

Quotas still serve as local enforcement of the size of the pool on a
per-mount basis.

A few caveats:

1) There is a race whereby the global surplus huge page counter is
incremented before a hugepage has allocated. Another process could then
try grow the pool, and fail to convert a surplus huge page to a normal
huge page and instead allocate a fresh huge page. I believe this is
benign, as no memory is leaked (the actual pages are still tracked
correctly) and the counters won't go out of sync.

2) Shrinking the static pool while a surplus is in effect will allow the
number of surplus huge pages to exceed the overcommit value. As long as
this condition holds, however, no more surplus huge pages will be
allowed on the system until one of the two sysctls are increased
sufficiently, or the surplus huge pages go out of use and are freed.

Successfully tested on x86_64 with the current libhugetlbfs snapshot,
modified to use the new sysctl.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-17 19:28:17 -08:00
Linus Torvalds 2c5ea0f2d8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  ACPI: move timer broadcast before busmaster disable
  clockevents: warn once when program_event() is called with negative expiry
  hrtimers: avoid overflow for large relative timeouts
2007-12-07 11:01:26 -08:00
Thomas Gleixner 167b1de3ee clockevents: warn once when program_event() is called with negative expiry
The hrtimer problem with large relative timeouts resulting in a
negative expiry time went unnoticed as there is no check in the
clockevents_program_event() code. Put a check there with a WARN_ONCE
to avoid such problems in the future.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-07 19:16:17 +01:00
Thomas Gleixner 62f0f61e66 hrtimers: avoid overflow for large relative timeouts
Relative hrtimers with a large timeout value might end up as negative
timer values, when the current time is added in hrtimer_start().

This in turn is causing the clockevents_set_next() function to set an
huge timeout and sleep for quite a long time when we have a clock
source which is capable of long sleeps like HPET. With PIT this almost
goes unnoticed as the maximum delta is ~27ms. The non-hrt/nohz code
sorts this out in the next timer interrupt, so we never noticed that
problem which has been there since the first day of hrtimers.

This bug became more apparent in 2.6.24 which activates HPET on more
hardware.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-07 19:16:17 +01:00
Ingo Molnar 8ced5f69e4 sched: enable early use of sched_clock()
some platforms have sched_clock() implementations that cannot be called
very early during wakeup. If it's called it might hang or crash in hard
to debug ways. So only call update_rq_clock() [which calls sched_clock()]
if sched_init() has already been called. (rq->idle is NULL before the
scheduler is initialized.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-07 19:02:47 +01:00
Ingo Molnar 5f9fa8a62d lockdep: make cli/sti annotation warnings clearer
make cli/sti annotation warnings easier to interpret.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-12-07 19:02:47 +01:00
Matthew Wilcox 009e577e07 Add wait_for_completion_killable
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:40:19 -05:00
Matthew Wilcox 294d5cc233 Add schedule_timeout_killable
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:40:07 -05:00
Liam R. Howlett ad776537cc Add mutex_lock_killable
Similar to mutex_lock_interruptible, it can be interrupted by a fatal
signal only.

Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:37:59 -05:00
Matthew Wilcox f776d12dd1 Add fatal_signal_pending
Like signal_pending, but it's only true for signals which are fatal to
this process

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:35:35 -05:00
Matthew Wilcox f021a3c2b1 Add TASK_WAKEKILL
Set TASK_WAKEKILL for TASK_STOPPED and TASK_TRACED, add TASK_KILLABLE and
use TASK_WAKEKILL in signal_wake_up()

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:35:28 -05:00
Matthew Wilcox 338077e54e exit: Use task_is_*
Also restructure the loop in do_wait()

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:35:17 -05:00
Matthew Wilcox e1abb39c60 signal: Use task_is_*
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:35:04 -05:00
Matthew Wilcox d9514f6c6b sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:34:59 -05:00
Matthew Wilcox 6618a3e275 ptrace: Use task_is_*
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:34:52 -05:00
Matthew Wilcox d2f60e5faa power: Use task_is_*
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:34:47 -05:00
Matthew Wilcox e64d66c8ed wait: Use TASK_NORMAL
Also move wake_up_locked() to be with the related functions

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:34:36 -05:00
Linus Torvalds 3743d33edf Tiny clean-up of OPROFILE/KPROBES configuration
Make the Kconfig.instrumentation file a bit easier on the eyes, and use
the new ARCH_SUPPORTS_OPROFILE for x86[-64].

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-06 09:41:12 -08:00
Ralf Baechle 00a5825332 Fix oprofile configuration breakage
The cleanup 09cadedbdc broke the oprofile
configuration for MIPS by allowing oprofile support to be built for
kernel models where oprofile doesn't have a chance in hell to work.

Just a dependecy list on a number of architectures is - surprise - broken
and should as per past discussions probably in most considered to be
broken in most cases.  So I introduce a dependency for the oprofile
configuration on ARCH_SUPPORTS_OPROFILE.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-06 09:37:03 -08:00
Linus Torvalds 7e1fb765c6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  futex: correctly return -EFAULT not -EINVAL
  lockdep: in_range() fix
  lockdep: fix debug_show_all_locks()
  sched: style cleanups
  futex: fix for futex_wait signal stack corruption
2007-12-05 09:27:46 -08:00
Linus Torvalds 2cfae2739b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC64]: Update defconfig.
  [SPARC]: Add missing of_node_put
  [SPARC64]: check for possible NULL pointer dereference
  [SPARC]: Add missing "space"
  [SPARC64]: Add missing "space"
  [SPARC64]: Add missing pci_dev_put
  [SYSCTL_CHECK]: Fix typo in KERN_SPARC_SCONS_PWROFF entry string.
  [SPARC64]: Missing mdesc_release() in ldc_init().
2007-12-05 09:25:53 -08:00
Pavel Emelyanov f1dad166e8 Avoid potential NULL dereference in unregister_sysctl_table
register_sysctl_table() can return NULL sometimes, e.g.  when kmalloc()
returns NULL or when sysctl check fails.

I've also noticed, that many (most?) code in the kernel doesn't check for
the return value from register_sysctl_table() and later simply calls the
unregister_sysctl_table() with potentially NULL argument.

This is unlikely on a common kernel configuration, but in case we're
dealing with modules and/or fault-injection support, there's a slight
possibility of an OOPS.

Changing all the users to check for return code from the registering does
not look like a good solution - there are too many code doing this and
failure in sysctl tables registration is not a good reason to abort module
loading (in most of the cases).

So I think, that we can just have this check in unregister_sysctl_table
just to avoid accidental OOPS-es (actually, the unregister_sysctl_table()
did exactly this, before the start_unregistering() appeared).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 09:21:20 -08:00
Eric W. Biederman 5cd17569fd fix clone(CLONE_NEWPID)
Currently we are complicating the code in copy_process, the clone ABI, and
if we fix the bugs sys_setsid itself, with an unnecessary open coded
version of sys_setsid.

So just simplify everything and don't special case the session and pgrp of
the initial process in a pid namespace.

Having this special case actually presents to user space the classic linux
startup conditions with session == pgrp == 0 for /sbin/init.

We already handle sending signals to processes in a child pid namespace.

We need to handle sending signals to processes in a parent pid namespace
for cases like SIGCHILD and SIGIO.

This makes nothing extra visible inside a pid namespace.  So this extra
special case appears to have no redeeming merits.

Further removing this special case increases the flexibility of how we can
use pid namespaces, by not requiring the initial process in a pid namespace
to be a daemon.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 09:21:18 -08:00
Thomas Gleixner cde898fa80 futex: correctly return -EFAULT not -EINVAL
return -EFAULT not -EINVAL. Found by review.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 15:46:09 +01:00
Oleg Nesterov 54561783ee lockdep: in_range() fix
Torsten Kaiser wrote:

| static inline int in_range(const void *start, const void *addr, const void *end)
| {
|         return addr >= start && addr <= end;
| }
| This  will return true, if addr is in the range of start (including)
| to end (including).
|
| But debug_check_no_locks_freed() seems does:
| const void *mem_to = mem_from + mem_len
| -> mem_to is the last byte of the freed range, that fits in_range
| lock_from = (void *)hlock->instance;
| -> first byte of the lock
| lock_to = (void *)(hlock->instance + 1);
| -> first byte of the next lock, not last byte of the lock that is being checked!
|
| The test is:
| if (!in_range(mem_from, lock_from, mem_to) &&
|                                         !in_range(mem_from, lock_to, mem_to))
|                         continue;
| So it tests, if the first byte of the lock is in the range that is freed ->OK
| And if the first byte of the *next* lock is in the range that is freed
| -> Not OK.

We can also simplify in_range checks, we need only 2 comparisons, not 4.
If the lock is not in memory range, it should be either at the left of range
or at the right.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-12-05 15:46:09 +01:00
Ingo Molnar 856848737b lockdep: fix debug_show_all_locks()
fix the oops that can be seen in:

   http://bugzilla.kernel.org/attachment.cgi?id=13828&action=view

it is not safe to print the locks of running tasks.

(even with this fix we have a small race - but this is a debug
 function after all.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-12-05 15:46:09 +01:00
Ingo Molnar 41a2d6cfa3 sched: style cleanups
style cleanup of various changes that were done recently.

no code changed:

      text    data     bss     dec     hex filename
     23680    2542      28   26250    668a sched.o.before
     23680    2542      28   26250    668a sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 15:46:09 +01:00
Steven Rostedt ce6bd420f4 futex: fix for futex_wait signal stack corruption
David Holmes found a bug in the -rt tree with respect to
pthread_cond_timedwait. After trying his test program on the latest git
from mainline, I found the bug was there too.  The bug he was seeing
that his test program showed, was that if one were to do a "Ctrl-Z" on a
process that was in the pthread_cond_timedwait, and then did a "bg" on
that process, it would return with a "-ETIMEDOUT" but early. That is,
the timer would go off early.

Looking into this, I found the source of the problem. And it is a rather
nasty bug at that.

Here's the relevant code from kernel/futex.c: (not in order in the file)

[...]
smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
                          struct timespec __user *utime, u32 __user *uaddr2,
                          u32 val3)
{
        struct timespec ts;
        ktime_t t, *tp = NULL;
        u32 val2 = 0;
        int cmd = op & FUTEX_CMD_MASK;

        if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) {
                if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
                        return -EFAULT;
                if (!timespec_valid(&ts))
                        return -EINVAL;

                t = timespec_to_ktime(ts);
                if (cmd == FUTEX_WAIT)
                        t = ktime_add(ktime_get(), t);
                tp = &t;
        }
[...]
        return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
}

[...]

long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
                u32 __user *uaddr2, u32 val2, u32 val3)
{
        int ret;
        int cmd = op & FUTEX_CMD_MASK;
        struct rw_semaphore *fshared = NULL;

        if (!(op & FUTEX_PRIVATE_FLAG))
                fshared = &current->mm->mmap_sem;

        switch (cmd) {
        case FUTEX_WAIT:
                ret = futex_wait(uaddr, fshared, val, timeout);

[...]

static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
                      u32 val, ktime_t *abs_time)
{
[...]
               struct restart_block *restart;
                restart = &current_thread_info()->restart_block;
                restart->fn = futex_wait_restart;
                restart->arg0 = (unsigned long)uaddr;
                restart->arg1 = (unsigned long)val;
                restart->arg2 = (unsigned long)abs_time;
                restart->arg3 = 0;
                if (fshared)
                        restart->arg3 |= ARG3_SHARED;
                return -ERESTART_RESTARTBLOCK;
[...]

static long futex_wait_restart(struct restart_block *restart)
{
        u32 __user *uaddr = (u32 __user *)restart->arg0;
        u32 val = (u32)restart->arg1;
        ktime_t *abs_time = (ktime_t *)restart->arg2;
        struct rw_semaphore *fshared = NULL;

        restart->fn = do_no_restart_syscall;
        if (restart->arg3 & ARG3_SHARED)
                fshared = &current->mm->mmap_sem;
        return (long)futex_wait(uaddr, fshared, val, abs_time);
}

So when the futex_wait is interrupt by a signal we break out of the
hrtimer code and set up or return from signal. This code does not return
back to userspace, so we set up a RESTARTBLOCK.  The bug here is that we
save the "abs_time" which is a pointer to the stack variable "ktime_t t"
from sys_futex.

This returns and unwinds the stack before we get to call our signal. On
return from the signal we go to futex_wait_restart, where we update all
the parameters for futex_wait and call it. But here we have a problem
where abs_time is no longer valid.

I verified this with print statements, and sure enough, what abs_time
was set to ends up being garbage when we get to futex_wait_restart.

The solution I did to solve this (with input from Linus Torvalds)
was to add unions to the restart_block to allow system calls to
use the restart with specific parameters.  This way the futex code now
saves the time in a 64bit value in the restart block instead of storing
it on the stack.

Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64
in thread_info.h, when there's a #ifdef __KERNEL__ just below that.
Not sure what that is there for.  If this turns out to be a problem, I've
tested this with using "unsigned int" for u32 and "unsigned long long" for
u64 and it worked just the same. I'm using u32 and u64 just to be
consistent with what the futex code uses.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 15:46:09 +01:00
David S. Miller 874a5f87f5 [SYSCTL_CHECK]: Fix typo in KERN_SPARC_SCONS_PWROFF entry string.
Based upon a report by Mikael Pettersson.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-05 05:37:56 -08:00
Ingo Molnar db292ca302 sched: default to more agressive yield for SCHED_BATCH tasks
do more agressive yield for SCHED_BATCH tuned tasks: they are all
about throughput anyway. This allows a gentler migration path for
any apps that relied on stronger yield.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-04 17:04:39 +01:00
Ingo Molnar 77034937dc sched: fix crash in sys_sched_rr_get_interval()
Luiz Fernando N. Capitulino reported that sched_rr_get_interval()
crashes for SCHED_OTHER tasks that are on an idle runqueue.

The fix is to return a 0 timeslice for tasks that are on an idle
runqueue. (and which are not running, obviously)

this also shrinks the code a bit:

   text    data     bss     dec     hex filename
  47903    3934     336   52173    cbcd sched.o.before
  47885    3934     336   52155    cbbb sched.o.after

Reported-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-04 17:04:39 +01:00
Linus Torvalds ca6435f188 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: cpu accounting controller (V2)
2007-12-03 08:21:06 -08:00
Al Viro b00296fb78 uml: add !UML dependencies
The previous commit ("uml: keep UML Kconfig in sync with x86") is not
enough, unfortunately.  If we go that way, we need to add dependencies
on !UML for several options.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-03 08:13:17 -08:00
Srivatsa Vaddagiri d842de871c sched: cpu accounting controller (V2)
Commit cfb5285660 removed a useful feature for
us, which provided a cpu accounting resource controller.  This feature would be
useful if someone wants to group tasks only for accounting purpose and doesnt
really want to exercise any control over their cpu consumption.

The patch below reintroduces the feature. It is based on Paul Menage's
original patch (Commit 62d0df6406), with
these differences:

        - Removed load average information. I felt it needs more thought (esp
	  to deal with SMP and virtualized platforms) and can be added for
	  2.6.25 after more discussions.
        - Convert group cpu usage to be nanosecond accurate (as rest of the cfs
	  stats are) and invoke cpuacct_charge() from the respective scheduler
	  classes
	- Make accounting scalable on SMP systems by splitting the usage
	  counter to be per-cpu
	- Move the code from kernel/cpu_acct.c to kernel/sched.c (since the
	  code is not big enough to warrant a new file and also this rightly
	  needs to live inside the scheduler. Also things like accessing
	  rq->lock while reading cpu usage becomes easier if the code lived in
	  kernel/sched.c)

The patch also modifies the cpu controller not to provide the same accounting
information.

Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com>

 Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran
 some simple tests like cpuspin (spin on the cpu), ran several tasks in
 the same group and timed them. Compared their time stamps with
 cpuacct.usage.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 20:04:49 +01:00
Scott James Remnant e6ceb32aa2 wait_task_stopped(): pass correct exit_code to wait_noreap_copyout()
In wait_task_stopped() exit_code already contains the right value for the
si_status member of siginfo, and this is simply set in the non WNOWAIT
case.

If you call waitid() with a stopped or traced process, you'll get the signal
in siginfo.si_status as expected -- however if you call waitid(WNOWAIT) at the
same time, you'll get the signal << 8 | 0x7f

Pass it unchanged to wait_noreap_copyout(); we would only need to shift it
and add 0x7f if we were returning it in the user status field and that
isn't used for any function that permits WNOWAIT.

Signed-off-by: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:55 -08:00
David Howells 9e6c1e6333 FRV: fix the extern declaration of kallsyms_num_syms
Fix the extern declaration of kallsyms_num_syms to indicate that the symbol
does not reside in the small-data storage space, and so may not be accessed
relative to the small data base register.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:54 -08:00
Pavel Emelyanov 32df81cbd5 Isolate the UTS namespace's domainname and hostname back
Commit 7d69a1f4a7 ("remove CONFIG_UTS_NS
and CONFIG_IPC_NS") by Cedric Le Goater accidentally removed the code
that prevented the uts->hostname and uts->domainname values from being
overwritten from another namespace.

In other words, setting hostname/domainname via sysfs (echo xxx >
/proc/sys/kernel/(host|domain)name) cased the new value to be set in
init UTS namespace only.

Return the isolation back.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:53 -08:00
Oleg Nesterov c895078355 wait_task_stopped(): don't use task_pid_nr_ns() lockless
wait_task_stopped(WNOWAIT) does task_pid_nr_ns() without tasklist/rcu lock,
we can read an already freed memory.  Use the cached pid_t value.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Looks-good-to: Roland McGrath <roland@redhat.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:52 -08:00
Ingo Molnar f95e0d1c2a sched: clean up kernel/sched_stat.h
clean up kernel/sched_stat.h.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Ingo Molnar c1a89740da sched: clean up overlong line in kernel/sched_debug.c
clean up overlong line in kernel/sched_debug.c.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Ingo Molnar deaf2227dd sched: clean up, move __sched_text_start/end to sched.h
move __sched_text_start/end to sched.h. No code changed:

   text    data     bss     dec     hex filename
  26582    2310      28   28920    70f8 sched.o.before
  26582    2310      28   28920    70f8 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Ingo Molnar 9a4e715914 sched: clean up sd_alloc_ctl_cpu_table() definition
clean up sd_alloc_ctl_cpu_table() definition.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Thomas Gleixner d393820446 softlockup: fix false positives on CONFIG_NOHZ
David Miller reported soft lockup false-positives that trigger
on NOHZ due to CPUs idling for more than 10 seconds.

The solution is touch the softlockup watchdog when we return from
idle. (by definition we are not 'locked up' when we were idle)

 http://bugzilla.kernel.org/show_bug.cgi?id=9409

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Linus Torvalds 8c27eba549 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6: (41 commits)
  [XFRM]: Fix leak of expired xfrm_states
  [ATM]: [he] initialize lock and tasklet earlier
  [IPV4]: Remove bogus ifdef mess in arp_process
  [SKBUFF]: Free old skb properly in skb_morph
  [IPV4]: Fix memory leak in inet_hashtables.h when NUMA is on
  [IPSEC]: Temporarily remove locks around copying of non-atomic fields
  [TCP] MTUprobe: Cleanup send queue check (no need to loop)
  [TCP]: MTUprobe: receiver window & data available checks fixed
  [MAINTAINERS]: tlan list is subscribers-only
  [SUNRPC]: Remove SPIN_LOCK_UNLOCKED
  [SUNRPC]: Make xprtsock.c:xs_setup_{udp,tcp}() static
  [PFKEY]: Sending an SADB_GET responds with an SADB_GET
  [IRDA]: Compilation for CONFIG_INET=n case
  [IPVS]: Fix compiler warning about unused register_ip_vs_protocol
  [ARP]: Fix arp reply when sender ip 0
  [IPV6] TCPMD5: Fix deleting key operation.
  [IPV6] TCPMD5: Check return value of tcp_alloc_md5sig_pool().
  [IPV4] TCPMD5: Use memmove() instead of memcpy() because we have overlaps.
  [IPV4] TCPMD5: Omit redundant NULL check for kfree() argument.
  ieee80211: Stop net_ratelimit/IEEE80211_DEBUG_DROP log pollution
  ...
2007-11-26 20:09:07 -08:00
Linus Torvalds 0685ab4fb8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: bump version of kernel/sched_debug.c
  sched: fix minimum granularity tunings
  sched: fix RLIMIT_CPU comment
  sched: fix kernel/acct.c comment
  sched: fix prev_stime calculation
  sched: don't forget to unlock uids_mutex on error paths
2007-11-26 19:42:08 -08:00
Linus Torvalds ff1ea52fa3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: fix APIC related bootup crash on Athlon XP CPUs
  time: add ADJ_OFFSET_SS_READ
  x86: export the symbol empty_zero_page on the 32-bit x86 architecture
  x86: fix kprobes_64.c inlining borkage
  pci: use pci=bfsort for HP DL385 G2, DL585 G2
  x86: correctly set UTS_MACHINE for "make ARCH=x86"
  lockdep: annotate do_debug() trap handler
  x86: turn off iommu merge by default
  x86: fix ACPI compile for LOCAL_APIC=n
  x86: printk kernel version in WARN_ON and other dump_stack users
  ACPI: Set max_cstate to 1 for early Opterons.
  x86: fix NMI watchdog & 'stopped time' problem
2007-11-26 19:41:28 -08:00
Linus Torvalds f4d53cedce Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio: fix net driver loop case where we fail to restart
  module: fix and elaborate comments
  virtio: fix module/device unloading
  lguest: Fix uninitialized members in example launcher
2007-11-26 19:17:19 -08:00
Ingo Molnar f7b9329e55 sched: bump version of kernel/sched_debug.c
bump version of kernel/sched_debug.c and remove CFS version
information from it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-26 21:21:49 +01:00
Zou Nan hai 722aab0c3b sched: fix minimum granularity tunings
increase the default minimum granularity some more - this gives us
more performance in aim7 benchmarks.

also correct some comments: we scale with ilog(ncpus) + 1.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-26 21:21:49 +01:00
Ingo Molnar bcbe4a0766 sched: fix kernel/acct.c comment
fix kernel/acct.c comment.

noticed by Lin Tan. Comment suggested by Olaf Kirch.

also see:

  http://bugzilla.kernel.org/show_bug.cgi?id=8220

Reported-by: tammy000@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-26 21:21:49 +01:00
Pavel Emelyanov 5e8869bb69 sched: don't forget to unlock uids_mutex on error paths
The commit

 commit 5cb350baf5
 Author: Dhaval Giani <dhaval@linux.vnet.ibm.com>
 Date:   Mon Oct 15 17:00:14 2007 +0200

    sched: group scheduling, sysfs tunables

introduced the uids_mutex and the helpers to lock/unlock it.
Unfortunately, the error paths of alloc_uid() were not patched
to unlock it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-26 21:21:49 +01:00
John Stultz 52bfb36050 time: add ADJ_OFFSET_SS_READ
Michael Kerrisk reported that a long standing bug in the adjtimex()
system call causes glibc's adjtime(3) function to deliver the wrong
results if 'delta' is NULL.

add the ADJ_OFFSET_SS_READ API detail, which will be used by glibc
to fix this API compatibility bug.

Also see: http://bugzilla.kernel.org/show_bug.cgi?id=6761

[ mingo@elte.hu: added patch description and made it backwards compatible ]

NOTE: the new flag is defined 0xa001 so that it returns -EINVAL on
older kernels - this way glibc can use it safely. Suggested by Ulrich
Drepper.

Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-26 20:42:19 +01:00
Heiko Carstens 37e3a6ac5a [S390] appldata: remove unused binary sysctls.
Remove binary sysctls that never worked due to missing strategy functions.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20 11:13:45 +01:00
Heiko Carstens 43ebbf119a [S390] cmm: remove unused binary sysctls.
Remove binary sysctls that never worked due to missing strategy functions.

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20 11:13:45 +01:00
Simon Horman 9055fa1f3d [IPVS]: Move remaining sysctl handlers over to CTL_UNNUMBERED
Switch the remaining IPVS sysctl entries over to to use CTL_UNNUMBERED,
I stronly doubt that anyone is using the sys_sysctl interface to
these variables.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-19 21:51:13 -08:00
Simon Horman 9e103fa6bd [IPVS]: Fix sysctl warnings about missing strategy in schedulers
sysctl table check failed: /net/ipv4/vs/lblc_expiration .3.5.21.19 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/lblcr_expiration .3.5.21.20 Missing strategy

Switch these entried over to use CTL_UNNUMBERED as clearly
the sys_syscal portion wasn't working.

This is along the same lines as Christian Borntraeger's patch that fixes
up entries with no stratergy in net/ipv4/ipvs/ip_vs_ctl.c

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-19 21:50:21 -08:00
Christian Borntraeger 611cd55b15 [IPVS]: Fix sysctl warnings about missing strategy
Running the latest git code I get the following messages during boot:
sysctl table check failed: /net/ipv4/vs/drop_entry .3.5.21.4 Missing strategy
[...]		  
sysctl table check failed: /net/ipv4/vs/drop_packet .3.5.21.5 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/secure_tcp .3.5.21.6 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/sync_threshold .3.5.21.24 Missing strategy

I removed the binary sysctl handler for those messages and also removed
the definitions in ip_vs.h. The alternative would be to implement a 
proper strategy handler, but syscall sysctl is deprecated.

There are other sysctl definitions that are commented out or work with 
the default sysctl_data strategy. I did not touch these. 

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-19 21:49:25 -08:00
Matti Linnanvuori 9a4b9708f1 module: fix and elaborate comments
Fix and elaborate comments.

Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-11-19 11:20:43 +11:00
David P. Reed fa6a1a554b ntp: fix typo that makes sync_cmos_clock erratic
Fix a typo in ntp.c that has caused updating of the persistent (RTC)
clock when synced to NTP to behave erratically.

When debugging a freeze that arises on my AMD64 machines when I
run the ntpd service, I added a number of printk's to monitor the
sync_cmos_clock procedure.  I discovered that it was not syncing to
cmos RTC every 11 minutes as documented, but instead would keep trying
every second for hours at a time.  The reason turned out to be a typo
in sync_cmos_clock, where it attempts to ensure that
update_persistent_clock is called very close to 500 msec. after a 1
second boundary (required by the PC RTC's spec). That typo referred to
"xtime" in one spot, rather than "now", which is derived from "xtime"
but not equal to it.  This makes the test erratic, creating a
"coin-flip" that decides when update_persistent_clock is called - when
it is called, which is rarely, it may be at any time during the one
second period, rather than close to 500 msec, so the value written is
needlessly incorrect, too.

Signed-off-by: David P. Reed
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-17 16:27:01 +01:00
Ingo Molnar 4307d1e5ad x86: ignore the sys_getcpu() tcache parameter
dont use the vgetcpu tcache - it's causing problems with tasks
migrating, they'll see the old cache up to a jiffy after the
migration, further increasing the costs of the migration.

In the worst case they see a complete bogus information from
the tcache, when a sys_getcpu() call "invalidated" the cache
info by incrementing the jiffies _and_ the cpuid info in the
cache and the following vdso_getcpu() call happens after
vdso_jiffies have been incremented.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-17 16:27:00 +01:00
Linus Torvalds 3c72f526df Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: reorder SCHED_FEAT_ bits
  sched: make sched_nr_latency static
  sched: remove activate_idle_task()
  sched: fix __set_task_cpu() SMP race
  sched: fix SCHED_FIFO tasks & FAIR_GROUP_SCHED
  sched: fix accounting of interrupts during guest execution on s390
2007-11-15 12:14:52 -08:00
Ingo Molnar 9612633a21 sched: reorder SCHED_FEAT_ bits
reorder SCHED_FEAT_ bits so that the used ones come first. Makes
tuning instructions easier.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:40 +01:00
Adrian Bunk 518b22e990 sched: make sched_nr_latency static
sched_nr_latency can now become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:40 +01:00
Dmitry Adamushko 94bc9a7bd9 sched: remove activate_idle_task()
cpu_down() code is ok wrt sched_idle_next() placing the 'idle' task not
at the beginning of the queue.

So get rid of activate_idle_task() and make use of activate_task() instead.
It is the same as activate_task(), except for the update_rq_clock(rq) call
that is redundant.

Code size goes down:

   text    data     bss     dec     hex filename
  47853    3934     336   52123    cb9b sched.o.before
  47828    3934     336   52098    cb82 sched.o.after

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:40 +01:00
Dmitry Adamushko ce96b5ac74 sched: fix __set_task_cpu() SMP race
Grant Wilson has reported rare SCHED_FAIR_USER crashes on his quad-core
system, which crashes can only be explained via runqueue corruption.

there is a narrow SMP race in __set_task_cpu(): after ->cpu is set up to
a new value, task_rq_lock(p, ...) can be successfuly executed on another
CPU. We must ensure that updates of per-task data have been completed by
this moment.

this bug has been hiding in the Linux scheduler for an eternity (we never
had any explicit barrier for task->cpu in set_task_cpu() - so the bug was
introduced in 2.5.1), but only became visible via set_task_cfs_rq() being
accidentally put after the task->cpu update. It also probably needs a
sufficiently out-of-order CPU to trigger.

Reported-by: Grant Wilson <grant.wilson@zen.co.uk>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:40 +01:00
Oleg Nesterov dae51f5620 sched: fix SCHED_FIFO tasks & FAIR_GROUP_SCHED
Suppose that the SCHED_FIFO task does

	switch_uid(new_user);

Now, p->se.cfs_rq and p->se.parent both point into the old
user_struct->tg because sched_move_task() doesn't call set_task_cfs_rq()
for !fair_sched_class case.

Suppose that old user_struct/task_group is freed/reused, and the task
does

	sched_setscheduler(SCHED_NORMAL);

__setscheduler() sets fair_sched_class, but doesn't update
->se.cfs_rq/parent which point to the freed memory.

This means that check_preempt_wakeup() doing

		while (!is_same_group(se, pse)) {
			se = parent_entity(se);
			pse = parent_entity(pse);
		}

may OOPS in a similar way if rq->curr or p did something like above.

Perhaps we need something like the patch below, note that
__setscheduler() can't do set_task_cfs_rq().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:40 +01:00
Christian Borntraeger 9778385db3 sched: fix accounting of interrupts during guest execution on s390
Currently the scheduler checks for PF_VCPU to decide if this timeslice
has to be accounted as guest time. On s390 host interrupts are not
disabled during guest execution. This causes theses interrupts to be
accounted as guest time if CONFIG_VIRT_CPU_ACCOUNTING is set. Solution
is to check if an interrupt triggered account_system_time. As the tick
is timer interrupt based, we have to subtract hardirq_offset.

I tested the patch on s390 with CONFIG_VIRT_CPU_ACCOUNTING and on
x86_64. Seems to work.

CC: Avi Kivity <avi@qumranet.com>
CC: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-15 20:57:39 +01:00