Commit Graph

10705 Commits

Author SHA1 Message Date
Christoph Hellwig 85fe4025c6 fs: do not assign default i_ino in new_inode
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Al Viro 7de9c6ee3e new helper: ihold()
Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Dave Chinner cffbc8aa33 fs: Convert nr_inodes and nr_unused to per-cpu counters
The number of inodes allocated does not need to be tied to the
addition or removal of an inode to/from a list. If we are not tied
to a list lock, we could update the counters when inodes are
initialised or destroyed, but to do that we need to convert the
counters to be per-cpu (i.e. independent of a lock). This means that
we have the freedom to change the list/locking implementation
without needing to care about the counters.

Based on a patch originally from Eric Dumazet.

[AV: cleaned up a bit, fixed build breakage on weird configs

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:09 -04:00
Eric Dumazet 7e360c38ab fs: allow for more than 2^31 files
Andrew,

Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.

Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())

Thanks !

[PATCH V4] fs: allow for more than 2^31 files

Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.

get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:18:20 -04:00
David Howells 5260562754 MN10300: Fix the PERCPU() alignment to allow for workqueues
In the MN10300 arch, we occasionally see an assertion being tripped in
alloc_cwqs() at the following line:

        /* just in case, make sure it's actually aligned */
  --->  BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
        return wq->cpu_wq.v ? 0 : -ENOMEM;

The values are:

        wa->cpu_wq.v => 0x902776e0
        align => 0x100

and align is calculated by the following:

        const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS,
                                   __alignof__(unsigned long long));

This is because the pointer in question (wq->cpu_wq.v) loses some of its
lower bits to control flags, and so the object it points to must be
sufficiently aligned to avoid the need to use those bits for pointing to
things.

Currently, 4 control bits and 4 colour bits are used in normal
circumstances, plus a debugging bit if debugging is set.  This requires
the cpu_workqueue_struct struct to be at least 256 bytes aligned (or 512
bytes aligned with debugging).

PERCPU() alignment on MN13000, however, is only 32 bytes as set in
vmlinux.lds.S.  So we set this to PAGE_SIZE (4096) to match most other
arches and stick a comment in alloc_cwqs() for anyone else who triggers
the assertion.

Reported-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mark Salter <msalter@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25 16:24:06 -07:00
Masami Hiramatsu 43948f5027 kprobes: Remove redundant text_mutex lock in optimize
Remove text_mutex locking in optimize_all_kprobes, because
this function doesn't modify text. It simply queues probes on
optimization list for kprobe_optimizer worker thread.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-25 15:51:55 +02:00
Linus Torvalds 229aebb873 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c
2010-10-24 13:41:39 -07:00
Rakib Mullick d4a6f3c32c sched_stat: Update sched_info_queue/dequeue() code comments
Remove some sched_info_queue(), sched_info_dequeue() code comment.
We no longer belongs to the era of O(1) and we don't use active or expired
array anymore.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <AANLkTi=REu0WzOp5N=nVT1=ZJ=ZA+MZFV+4CHSJ3Q-Yv@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-24 13:29:01 +02:00
Joe Perches aa7b250c25 tracing: Fix 'faild' -> 'failed' typo
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Kosina <trivial@kernel.org>
LKML-Reference: <cd9855af60d7d90e9f55fc7afd0ed23fcdaa6f52.1287724261.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-23 20:06:38 +02:00
Ingo Molnar b8ecad8b2f Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent 2010-10-23 20:05:43 +02:00
Linus Torvalds 02f36038c5 Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softirqs: Make wakeup_softirqd static

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, asm: Restore parentheses around one pushl_cfi argument
  x86, asm: Fix ancient-GAS workaround
  x86, asm: Fix CFI macro invocations to deal with shortcomings in gas

* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA

* 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: HPET force enable for CX700 / VIA Epia LT

* 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, setup: Use string copy operation to optimze copy in kernel compression

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, UV: Use allocated buffer in tlb_uv.c:tunables_read()

* 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
2010-10-23 08:25:36 -07:00
Linus Torvalds 8814011679 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kdb,debug_core: adjust master cpu switch logic against new debug_core locking
  debug_core: refactor locking for master/slave cpus
  x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()
  debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
  kdb,kgdb: fix sparse fixups
  kdb: Fix oops in kdb_unregister
  kdb,ftdump: Remove reference to internal kdb include
  kdb: Allow kernel loadable modules to add kdb shell functions
  debug_core: stop rcu warnings on kernel resume
  debug_core: move all watch dog syncs to a single function
  x86,kgdb: fix debugger hw breakpoint test regression in 2.6.35
2010-10-22 20:35:12 -07:00
Linus Torvalds 91b745016c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove in_workqueue_context()
  workqueue: Clarify that schedule_on_each_cpu is synchronous
  memory_hotplug: drop spurious calls to flush_scheduled_work()
  shpchp: update workqueue usage
  pciehp: update workqueue usage
  isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
  workqueue: add and use WQ_MEM_RECLAIM flag
  workqueue: fix HIGHPRI handling in keep_working()
  workqueue: add queue_work and activate_work trace points
  workqueue: prepare for more tracepoints
  workqueue: implement flush[_delayed]_work_sync()
  workqueue: factor out start_flush_work()
  workqueue: cleanup flush/cancel functions
  workqueue: implement alloc_ordered_workqueue()

Fix up trivial conflict in fs/gfs2/main.c as per Tejun
2010-10-22 17:13:10 -07:00
Jason Wessel 495363d380 kdb,debug_core: adjust master cpu switch logic against new debug_core locking
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution.  Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.

The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:13 -05:00
Jason Wessel dfee3a7b92 debug_core: refactor locking for master/slave cpus
For quite some time there have been problems with memory barriers and
various races with NMI on multi processor systems using the kernel
debugger.  The algorithm for entering the kernel debug core and
resuming kernel execution was racy and had several known edge case
problems with attempting to debug something on a heavily loaded system
using breakpoints that are hit repeatedly and quickly.

The prior "locking" design entry worked as follows:

  * The atomic counter kgdb_active was used with atomic exchange in
    order to elect a master cpu out of all the cpus that may have
    taken a debug exception.
  * The master cpu increments all elements of passive_cpu_wait[].
  * The master cpu issues the round up cpus message.
  * Each "slave cpu" that enters the debug core increments its own
    element in cpu_in_kgdb[].
  * Each "slave cpu" spins on passive_cpu_wait[] until it becomes 0.
  * The master cpu debugs the system.

The new scheme removes the two arrays of atomic counters and replaces
them with 2 single counters.  One counter is used to count the number
of cpus waiting to become a master cpu (because one or more hit an
exception). The second counter is use to indicate how many cpus have
entered as slave cpus.

The new entry logic works as follows:

  * One or more cpus enters via kgdb_handle_exception() and increments
    the masters_in_kgdb. Each cpu attempts to get the spin lock called
    dbg_master_lock.
  * The master cpu sets kgdb_active to the current cpu.
  * The master cpu takes the spinlock dbg_slave_lock.
  * The master cpu asks to round up all the other cpus.
  * Each slave cpu that is not already in kgdb_handle_exception()
    will enter and increment slaves_in_kgdb.  Each slave will now spin
    try_locking on dbg_slave_lock.
  * The master cpu waits for the sum of masters_in_kgdb and slaves_in_kgdb
    to be equal to the sum of the online cpus.
  * The master cpu debugs the system.

In the new design the kgdb_active can only be changed while holding
dbg_master_lock.  Stress testing has not turned up any further
entry/exit races that existed in the prior locking design.  The prior
locking design suffered from atomic variables not being truly atomic
(in the capacity as used by kgdb) along with memory barrier races.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
2010-10-22 15:34:13 -05:00
Dongdong Deng c1bb9a9c19 debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
The slave cpus do not have the hw breakpoints disabled upon entry to
the debug_core and as a result could cause unrecoverable recursive
faults on badly placed breakpoints, or get out of sync with the arch
specific hw breakpoint operations.

This patch addresses the problem by invoking kgdb_disable_hw_debug()
earlier in kgdb_enter_cpu for each cpu that enters the debug core.

The hw breakpoint dis/enable flow should be:

master_debug_cpu   slave_debug_cpu
         \              /
          kgdb_cpu_enter
                |
        kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint
                |
 do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu..
                |
        correct_hw_break --> correct/install the enabled hw_breakpoint
                |
           leave_kgdb

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel 91b152aa85 kdb,kgdb: fix sparse fixups
Fix the following sparse warnings:

kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static?
kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static?
kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces)
kgdb.c:652:26:    expected void const *ptr
kgdb.c:652:26:    got struct perf_event *[noderef] <asn:3>*pev

The one in kgdb.c required the (void * __force) because of the return
code from register_wide_hw_breakpoint looking like:

        return (void __percpu __force *)ERR_PTR(err);

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel 75d14edee5 kdb: Fix oops in kdb_unregister
Nothing should try to use kdb_commands directly as sometimes it is
null.  Instead, use the for_each_kdbcmd() iterator.

This particular problem dates back to the initial kdb merge (2.6.35),
but at that point nothing was dynamically unregistering commands from
the kdb shell.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel e3bda3ac33 kdb,ftdump: Remove reference to internal kdb include
Now that include/linux/kdb.h properly exports all the functions
required to dynamically add a kdb shell command, the reference to the
private kdb header can be removed.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:11 -05:00
Jason Wessel f7030bbc44 kdb: Allow kernel loadable modules to add kdb shell functions
In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.

Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:11 -05:00
Jason Wessel fb70b5888b debug_core: stop rcu warnings on kernel resume
When returning from the kernel debugger reset the rcu jiffies_stall
value to prevent the rcu stall detector from sending NMI events which
invoke a stack dump for each cpu in the system.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:10 -05:00
Jason Wessel 16cdc628c3 debug_core: move all watch dog syncs to a single function
Move the various clock and watch dog syncs to a single function in
advance of adding another sync for the rcu stall detector.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:10 -05:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Linus Torvalds 79f14b7c56 Merge branch 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits)
  BKL: remove BKL from freevxfs
  BKL: remove BKL from qnx4
  autofs4: Only declare function when CONFIG_COMPAT is defined
  autofs: Only declare function when CONFIG_COMPAT is defined
  ncpfs: Lock socket in ncpfs while setting its callbacks
  fs/locks.c: prepare for BKL removal
  BKL: Remove BKL from ncpfs
  BKL: Remove BKL from OCFS2
  BKL: Remove BKL from squashfs
  BKL: Remove BKL from jffs2
  BKL: Remove BKL from ecryptfs
  BKL: Remove BKL from afs
  BKL: Remove BKL from USB gadgetfs
  BKL: Remove BKL from autofs4
  BKL: Remove BKL from isofs
  BKL: Remove BKL from fat
  BKL: Remove BKL from ext2 filesystem
  BKL: Remove BKL from do_new_mount()
  BKL: Remove BKL from cgroup
  BKL: Remove BKL from NTFS
  ...
2010-10-22 10:52:01 -07:00
Linus Torvalds 5704e44d28 Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  BKL: introduce CONFIG_BKL.
  dabusb: remove the BKL
  sunrpc: remove the big kernel lock
  init/main.c: remove BKL notations
  blktrace: remove the big kernel lock
  rtmutex-tester: make it build without BKL
  dvb-core: kill the big kernel lock
  dvb/bt8xx: kill the big kernel lock
  tlclk: remove big kernel lock
  fix rawctl compat ioctls breakage on amd64 and itanic
  uml: kill big kernel lock
  parisc: remove big kernel lock
  cris: autoconvert trivial BKL users
  alpha: kill big kernel lock
  isapnp: BKL removal
  s390/block: kill the big kernel lock
  hpet: kill BKL, add compat_ioctl
2010-10-22 10:43:11 -07:00
Thomas Gleixner 2656c36699 genirq: Warn if enable_irq is called before irq is set up
The recent changes in the genirq core unearthed a bug in arch/um which
called enable_irq() before the interrupt was set up.

Warn and return instead of crashing the machine with a NULL pointer
dereference.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Weinberger <richard@nod.at>
2010-10-22 16:10:29 +02:00
Ingo Molnar eea4a0b19a Merge branch 'tip/perf/core-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent 2010-10-22 15:13:45 +02:00
Stephane Eranian d7842da470 perf_events: Fix for transaction recovery in group_sched_in()
This new version (see commit 8e5fc1a) is much simpler and ensures that
in case of error in group_sched_in() during event_sched_in(), the
events up to the failed event go through regular event_sched_out().
But the failed event and the remaining events in the group have their
timings adjusted as if they had also gone through event_sched_in() and
event_sched_out(). This ensures timing uniformity across all events in
a group. This also takes care of the tstamp_stopped problem in case
the group could never be scheduled. The tstamp_stopped is updated as
if the event had actually run.

With this patch, the following now reports correct time_enabled,
in case the NMI watchdog is active:

$ task -e unhalted_core_cycles,instructions_retired,baclears,baclears
noploop 1
noploop for 1 seconds

0 unhalted_core_cycles (100.00% scaling, ena=997,552,872, run=0)
0 instructions_retired (100.00% scaling, ena=997,552,872, run=0)
0 baclears (100.00% scaling, ena=997,552,872, run=0)
0 baclears (100.00% scaling, ena=997,552,872, run=0)

And the older test case also works:

$ task -einstructions_retired,baclears,baclears -e
unhalted_core_cycles,baclears,baclears sleep 5

1680885 instructions_retired (69.39% scaling, ena=950756, run=291006)
  10735 baclears (69.39% scaling, ena=950756, run=291006)
  10735 baclears (69.39% scaling, ena=950756, run=291006)

      0 unhalted_core_cycles (100.00% scaling, ena=817932, run=0)
      0 baclears (100.00% scaling, ena=817932, run=0)
      0 baclears (100.00% scaling, ena=817932, run=0)

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cbeeebc.8ee7d80a.5a28.0d5f@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-22 14:18:27 +02:00
Stephane Eranian 9ffcfa6f1f perf_events: Revert: Fix transaction recovery in group_sched_in()
This patch reverts commit 8e5fc1a (perf_events: Fix transaction
recovery in group_sched_in()) because it had one flaw in case the
group could never be scheduled. It would cause time_enabled to get
negative.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cbeeeb7.0aefd80a.6e40.0e2f@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-22 14:18:27 +02:00
Peter Zijlstra b2b5ce022a sched, cgroup: Fixup broken cgroup movement
Dima noticed that we fail to correct the ->vruntime of sleeping tasks
when we move them between cgroups.

Reported-by: Dima Zavin <dima@android.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1287150604.29097.1513.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-22 14:16:45 +02:00
Linus Torvalds d4429f608a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (71 commits)
  powerpc/44x: Update ppc44x_defconfig
  powerpc/watchdog: Make default timeout for Book-E watchdog a Kconfig option
  fsl_rio: Add comments for sRIO registers.
  powerpc/fsl-booke: Add e55xx (64-bit) smp defconfig
  powerpc/fsl-booke: Add p5020 DS board support
  powerpc/fsl-booke64: Use TLB CAMs to cover linear mapping on FSL 64-bit chips
  powerpc/fsl-booke: Add support for FSL Arch v1.0 MMU in setup_page_sizes
  powerpc/fsl-booke: Add support for FSL 64-bit e5500 core
  powerpc/85xx: add cache-sram support
  powerpc/85xx: add ngPIXIS FPGA device tree node to the P1022DS board
  powerpc: Fix compile error with paca code on ppc64e
  powerpc/fsl-booke: Add p3041 DS board support
  oprofile/fsl emb: Don't set MSR[PMM] until after clearing the interrupt.
  powerpc/fsl-booke: Add PCI device ids for P2040/P3041/P5010/P5020 QoirQ chips
  powerpc/mpc8xxx_gpio: Add support for 'qoriq-gpio' controllers
  powerpc/fsl_booke: Add support to boot from core other than 0
  powerpc/p1022: Add probing for individual DMA channels
  powerpc/fsl_soc: Search all global-utilities nodes for rstccr
  powerpc: Fix invalid page flags in create TLB CAM path for PTE_64BIT
  powerpc/mpc83xx: Support for MPC8308 P1M board
  ...

Fix up conflict with the generic irq_work changes in arch/powerpc/kernel/time.c
2010-10-21 21:19:54 -07:00
Linus Torvalds 3044100e58 Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits)
  x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
  xen: Cope with unmapped pages when initializing kernel pagetable
  memblock, bootmem: Round pfn properly for memory and reserved regions
  memblock: Annotate memblock functions with __init_memblock
  memblock: Allow memblock_init to be called early
  memblock/arm: Fix memblock_region_is_memory() typo
  x86, memblock: Remove __memblock_x86_find_in_range_size()
  memblock: Fix wraparound in find_region()
  x86-32, memblock: Make add_highpages honor early reserved ranges
  x86, memblock: Fix crashkernel allocation
  arm, memblock: Fix the sparsemem build
  memblock: Fix section mismatch warnings
  powerpc, memblock: Fix memblock API change fallout
  memblock, microblaze: Fix memblock API change fallout
  x86: Remove old bootmem code
  x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
  x86: Remove not used early_res code
  x86, memblock: Replace e820_/_early string with memblock_
  x86: Use memblock to replace early_res
  x86, memblock: Use memblock_debug to control debug message print out
  ...

Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile
2010-10-21 18:52:11 -07:00
Linus Torvalds b5153163ed Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits)
  arm: remove machine_desc.io_pg_offst and .phys_io
  arm: use addruart macro to establish debug mappings
  arm: return both physical and virtual addresses from addruart
  arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC
  ARM: make struct machine_desc definition coherent with its comment
  eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free
  cpuimx27: fix compile when ULPI is selected
  mach-pcm037_eet: fix compile errors
  Fixing ethernet driver compilation error for i.MX31 ADS board
  cpuimx51: update board support
  mx5: add cpuimx51sd module and its baseboard
  iomux-mx51: fix GPIO_1_xx 's IOMUX configuration
  imx-esdhc: update devices registration
  mx51: add resources for SD/MMC on i.MX51
  iomux-mx51: fix SD1 and SD2's iomux configuration
  clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability
  clock-mx51: factorize clk_set_parent and clk_get_rate
  eukrea_mbimxsd: add support for DVI displays
  cpuimx25 & cpuimx35: fix OTG port registration in host mode
  i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
  ...
2010-10-21 16:42:32 -07:00
Linus Torvalds a8cbf22559 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (26 commits)
  PM / Wakeup: Show wakeup sources statistics in debugfs
  PM: Introduce library for device-specific OPPs (v7)
  PM: Add sysfs attr for rechecking dev hash from PM trace
  PM: Lock PM device list mutex in show_dev_hash()
  PM / Runtime: Remove idle notification after failing suspend
  PM / Hibernate: Modify signature used to mark swap
  PM / Runtime: Reduce code duplication in core helper functions
  PM: Allow wakeup events to abort freezing of tasks
  PM: runtime: add missed pm_request_autosuspend
  PM / Hibernate: Make some boot messages look less scary
  PM / Runtime: Implement autosuspend support
  PM / Runtime: Add no_callbacks flag
  PM / Runtime: Combine runtime PM entry points
  PM / Runtime: Merge synchronous and async runtime routines
  PM / Runtime: Replace boolean arguments with bitflags
  PM / Runtime: Move code in drivers/base/power/runtime.c
  sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()
  PM: Fix potential issue with failing asynchronous suspend
  PM / Wakeup: Introduce wakeup source objects and event statistics (v3)
  PM: Fix signed/unsigned warning in dpm_show_time()
  ...
2010-10-21 14:53:17 -07:00
Linus Torvalds 4a60cfa945 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (96 commits)
  apic, x86: Use BIOS settings for IBS and MCE threshold interrupt LVT offsets
  apic, x86: Check if EILVT APIC registers are available (AMD only)
  x86: ioapic: Call free_irte only if interrupt remapping enabled
  arm: Use ARCH_IRQ_INIT_FLAGS
  genirq, ARM: Fix boot on ARM platforms
  genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build
  x86: Switch sparse_irq allocations to GFP_KERNEL
  genirq: Switch sparse_irq allocator to GFP_KERNEL
  genirq: Make sparse_lock a mutex
  x86: lguest: Use new irq allocator
  genirq: Remove the now unused sparse irq leftovers
  genirq: Sanitize dynamic irq handling
  genirq: Remove arch_init_chip_data()
  x86: xen: Sanitise sparse_irq handling
  x86: Use sane enumeration
  x86: uv: Clean up the direct access to irq_desc
  x86: Make io_apic.c local functions static
  genirq: Remove irq_2_iommu
  x86: Speed up the irq_remapped check in hot pathes
  intr_remap: Simplify the code further
  ...

Fix up trivial conflicts in arch/x86/Kconfig
2010-10-21 14:11:46 -07:00
Linus Torvalds 62bea97f54 Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ntp: Clamp PLL update interval
2010-10-21 14:08:08 -07:00
Linus Torvalds b61f6a57f1 Merge branch 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix kernel-doc notation & typos
  futex: Add lock context annotations
  futex: Mark restart_block.futex.uaddr[2] __user
  futex: Change 3rd arg of fetch_robust_entry() to unsigned int*
2010-10-21 14:06:17 -07:00
Linus Torvalds 0575db881d Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix errors in nested key ref-counting
2010-10-21 14:05:55 -07:00
Linus Torvalds bc4016f481 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
  sched: Export account_system_vtime()
  sched: Call tick_check_idle before __irq_enter
  sched: Remove irq time from available CPU power
  sched: Do not account irq time to current task
  x86: Add IRQ_TIME_ACCOUNTING
  sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time
  sched: Add a PF flag for ksoftirqd identification
  sched: Consolidate account_system_vtime extern declaration
  sched: Fix softirq time accounting
  sched: Drop group_capacity to 1 only if local group has extra capacity
  sched: Force balancing on newidle balance if local group has capacity
  sched: Set group_imb only a task can be pulled from the busiest cpu
  sched: Do not consider SCHED_IDLE tasks to be cache hot
  sched: Drop all load weight manipulation for RT tasks
  sched: Create special class for stop/migrate work
  sched: Unindent labels
  sched: Comment updates: fix default latency and granularity numbers
  tracing/sched: Add sched_pi_setprio tracepoint
  sched: Give CPU bound RT tasks preference
  sched: Try not to migrate higher priority RT tasks
  ...
2010-10-21 12:55:43 -07:00
Linus Torvalds 5d70f79b5e Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (163 commits)
  tracing: Fix compile issue for trace_sched_wakeup.c
  [S390] hardirq: remove pointless header file includes
  [IA64] Move local_softirq_pending() definition
  perf, powerpc: Fix power_pmu_event_init to not use event->ctx
  ftrace: Remove recursion between recordmcount and scripts/mod/empty
  jump_label: Add COND_STMT(), reducer wrappery
  perf: Optimize sw events
  perf: Use jump_labels to optimize the scheduler hooks
  jump_label: Add atomic_t interface
  jump_label: Use more consistent naming
  perf, hw_breakpoint: Fix crash in hw_breakpoint creation
  perf: Find task before event alloc
  perf: Fix task refcount bugs
  perf: Fix group moving
  irq_work: Add generic hardirq context callbacks
  perf_events: Fix transaction recovery in group_sched_in()
  perf_events: Fix bogus AMD64 generic TLB events
  perf_events: Fix bogus context time tracking
  tracing: Remove parent recording in latency tracer graph options
  tracing: Use one prologue for the preempt irqs off tracer function tracers
  ...
2010-10-21 12:54:49 -07:00
Linus Torvalds 888a6f77e0 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits)
  sched: fix RCU lockdep splat from task_group()
  rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
  sched: suppress RCU lockdep splat in task_fork_fair
  net: suppress RCU lockdep false positive in sock_update_classid
  rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held
  rcu: Add advice to PROVE_RCU_REPEATEDLY kernel config parameter
  rcu: Add tracing data to support queueing models
  rcu: fix sparse errors in rcutorture.c
  rcu: only one evaluation of arg in rcu_dereference_check() unless sparse
  kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC
  rcu: fix _oddness handling of verbose stall warnings
  rcu: performance fixes to TINY_PREEMPT_RCU callback checking
  rcu: upgrade stallwarn.txt documentation for CPU-bound RT processes
  vhost: add __rcu annotations
  rcu: add comment stating that list_empty() applies to RCU-protected lists
  rcu: apply TINY_PREEMPT_RCU read-side speedup to TREE_PREEMPT_RCU
  rcu: combine duplicate code, courtesy of CONFIG_PREEMPT_RCU
  rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods
  rcu: document ways of stalling updates in low-memory situations
  rcu: repair code-duplication FIXMEs
  ...
2010-10-21 12:54:12 -07:00
Linus Torvalds 31b7eab27a Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Check the depth of subclass
  lockdep: Add improved subclass caching
  affs: Use sema_init instead of init_MUTEX
  hfs: Convert tree_lock to mutex
  arm: Bcmring: semaphore cleanup
  printk: Make console_sem a semaphore not a pseudo mutex
  drivers/macintosh/adb: Do not claim that the semaphore is a mutex
  parport: Semaphore cleanup
  irda: Semaphore cleanup
  net: Wan/cosa.c: Convert "mutex" to semaphore
  net: Ppp_async: semaphore cleanup
  hamradio: Mkiss: semaphore cleanup
  hamradio: 6pack: semaphore cleanup
  net: 3c527: semaphore cleanup
  input: Serio/hp_sdc: semaphore cleanup
  input: Serio/hil_mlc: semaphore cleanup
  input: Misc/hp_sdc_rtc: semaphore cleanup
  lockup_detector: Make callback function static
  lockup detector: Fix grammar by adding a missing "to" in the comments
  lockdep: Remove __debug_show_held_locks
2010-10-21 12:49:31 -07:00
Thomas Gleixner f4bc6bb2d5 tracing: Cleanup the convoluted softirq tracepoints
With the addition of trace_softirq_raise() the softirq tracepoint got
even more convoluted. Why the tracepoints take two pointers to assign
an integer is beyond my comprehension.

But adding an extra case which treats the first pointer as an unsigned
long when the second pointer is NULL including the back and forth
type casting is just horrible.

Convert the softirq tracepoints to take a single unsigned int argument
for the softirq vector number and fix the call sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <alpine.LFD.2.00.1010191428560.6815@localhost6.localdomain6>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: mathieu.desnoyers@efficios.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2010-10-21 16:50:29 +02:00
Steven Rostedt dd49a38cf3 tracing: Do not limit the size of the number of CPU buffers
The tracing per_cpu buffers were limited to 999 CPUs for a mear
savings in stack space of a char array. Up the array to 30 characters
which is more than enough to hold a 64 bit number.

Reported-by: Robin Holt <holt@sgi.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-21 08:55:06 -04:00
KOSAKI Motohiro b0ae198113 security: remove unused parameter from security_task_setscheduler()
All security modules shouldn't change sched_param parameter of
security_task_setscheduler().  This is not only meaningless, but also
make a harmful result if caller pass a static variable.

This patch remove policy and sched_param parameter from
security_task_setscheduler() becuase none of security module is
using it.

Cc: James Morris <jmorris@namei.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:44 +11:00
Steven Rostedt b8b2663bd7 ring-buffer: Remove unused macro RB_TIMESTAMPS_PER_PAGE
With the binding of time extends to events we no longer need to use
the macro RB_TIMESTAMPS_PER_PAGE. Remove it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 15:17:58 -04:00
Steven Rostedt d9abde2138 ring-buffer: Micro-optimize with some strategic inlining
By using inline and noinline, we are able to make the fast path of
recording an event 4% faster.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 15:17:57 -04:00
Steven Rostedt 140ff89127 ring-buffer: Remove condition to add timestamp in fast path
There's a condition to check if we should add a time extend or
not in the fast path. But this condition is racey (in the sense
that we can add a unnecessary time extend, but nothing that
can break anything). We later check if the time or event time
delta should be zero or have real data in it (not racey), making
this first check redundant.

This check may help save space once in a while, but really is
not worth the hassle to try to save some space that happens at
most 134 ms at a time.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 15:17:56 -04:00
Steven Rostedt 69d1b839f7 ring-buffer: Bind time extend and data events together
When the time between two timestamps is greater than
2^27 nanosecs (~134 ms) a time extend event is added that extends
the time difference to 59 bits (~18 years). This is due to
events only having a 27 bit field to store time.

Currently this time extend is a separate event. We add it just before
the event data that is being written to the buffer. But before
the event data is committed, the event data can also be discarded (as
with the case of filters). But because the time extend has already been
committed, it will stay in the buffer.

If lots of events are being filtered and no event is being
written, then every 134ms a time extend can be added to the buffer
without any data attached. To keep from filling the entire buffer
with time extends, a time extend will never be the first event
in a page because the page timestamp can be used. Time extends can
only fill the rest of a page with some data at the beginning.

This patch binds the time extend with the data. The difference here
is that the time extend is not committed before the data is added.
Instead, when a time extend is needed, the space reserved on
the ring buffer is the time extend + the data event size. The
time extend is added to the first part of the reserved block and
the data is added to the second. The time extend event is passed
back to the reserver, but since the reserver also uses a function
to find the data portion of the reserved block, no changes to the
ring buffer interface need to be made.

When a commit is discarded, we now remove both the time extend and
the event. With this approach no more than one time extend can
be in the buffer in a row. Data must always follow a time extend.

Thanks to Mathieu Desnoyers for suggesting this idea.

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 15:17:16 -04:00
Steven Rostedt f25106aeab ring-buffer: Pass delta by value and not by reference
The delta between events is passed to the timestamp code by reference
and the timestamp code will reset the value. But it can be reset
from the caller. No need to pass it in by reference.

By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the delta in a register and not
worry about updating the reference.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 12:40:12 -04:00
Steven Rostedt e8bc43e84f ring-buffer: Pass timestamp by value and not by reference
The original code for the ring buffer had locations that modified
the timestamp and that change was used by the callers. Now,
the timestamp is not reused by the callers and there is no reason
to pass it by reference.

By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the timestamp in a register and not
worry about updating the reference.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20 10:58:02 -04:00
Ingo Molnar 14d4962dc8 Merge branch 'linus' into irq/core
Merge reason: update to almost-final-.36

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-20 04:38:59 +02:00
Russell King 809b4e00ba Merge branch 'devel-stable' into devel 2010-10-19 22:06:36 +01:00
Ingo Molnar 750ed158bf Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-10-19 20:41:38 +02:00
Steven Rostedt 747e94ae3d ring-buffer: Make write slow path out of line
Gcc inlines the slow path of the ring buffer write which can
hurt performance. This patch simply forces the slow path function
rb_move_tail() to always be a function.

The ring_buffer_benchmark module with reader_disabled=1 shows that
this patch changes the time to record an event from 135 ns to
132 ns. (3 ns or 2.22% improvement)

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-19 13:22:36 -04:00
Steven Rostedt 7e40798f40 tracing: Fix compile issue for trace_sched_wakeup.c
The function start_func_tracer() was incorrectly added in the
 #ifdef CONFIG_FUNCTION_TRACER condition, but is still used even
when function tracing is not enabled.

The calls to register_ftrace_function() and register_ftrace_graph()
become nops (and their arguments are even ignored), thus there is
no reason to hide start_func_tracer() when function tracing is
not enabled.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-19 10:56:19 -04:00
Darren Hart 7ada876a87 futex: Fix errors in nested key ref-counting
futex_wait() is leaking key references due to futex_wait_setup()
acquiring an additional reference via the queue_lock() routine. The
nested key ref-counting has been masking bugs and complicating code
analysis. queue_lock() is only called with a previously ref-counted
key, so remove the additional ref-counting from the queue_(un)lock()
functions.

Also futex_wait_requeue_pi() drops one key reference too many in
unqueue_me_pi(). Remove the key reference handling from
unqueue_me_pi(). This was paired with a queue_lock() in
futex_lock_pi(), so the count remains unchanged.

Document remaining nested key ref-counting sites.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-and-tested-by: Matthieu Fertré<matthieu.fertre@kerlabs.com>
Reported-by: Louis Rilling<louis.rilling@kerlabs.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4CBB17A8.70401@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2010-10-19 11:41:54 +02:00
Arnd Bergmann 01b284f9b6 blktrace: remove the big kernel lock
According to Jens, this code does not need the BKL at all,
it is sufficiently serialized by bd_mutex.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2010-10-19 11:29:57 +02:00
Arnd Bergmann 0fc86c7bd9 rtmutex-tester: make it build without BKL
The big kernel lock is going away, so make sure
that if it is disabled by Kconfig, we do not
try to validate it, which would result in
compile errors.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2010-10-19 11:29:56 +02:00
Tejun Heo daaae6b010 workqueue: remove in_workqueue_context()
Commit a25909a4 (lockdep: Add an in_workqueue_context() lockdep-based
test function) added in_workqueue_context() but there hasn't been any
in-kernel user and the lockdep annotation in workqueue is scheduled to
change.  Remove the unused function.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-10-19 11:28:15 +02:00
Tejun Heo 31ddd871fc workqueue: Clarify that schedule_on_each_cpu is synchronous
The documentation for schedule_on_each_cpu() states that it calls a
function on each online CPU from keventd.  This can easily be
interpreted as an asyncronous call because the description does not
mention that flush_work is called.  Clarify that it is synchronous.

tj: rephrased a bit

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-10-19 11:14:49 +02:00
Russell King 23beab76b4 Merge branches 'at91', 'dcache', 'ftrace', 'hwbpt', 'misc', 'mmci', 's3c', 'st-ux' and 'unwind' into devel 2010-10-18 22:34:25 +01:00
Ingo Molnar b7dadc3879 sched: Export account_system_vtime()
KVM uses it for example:

 ERROR: "account_system_vtime" [arch/x86/kvm/kvm.ko] undefined!

Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:30 +02:00
Venkatesh Pallipadi d267f87fb8 sched: Call tick_check_idle before __irq_enter
When CPU is idle and on first interrupt, irq_enter calls tick_check_idle()
to notify interruption from idle. But, there is a problem if this call
is done after __irq_enter, as all routines in __irq_enter may find
stale time due to yet to be done tick_check_idle.

Specifically, trace calls in __irq_enter when they use global clock and also
account_system_vtime change in this patch as it wants to use sched_clock_cpu()
to do proper irq timing.

But, tick_check_idle was moved after __irq_enter intentionally to
prevent problem of unneeded ksoftirqd wakeups by the commit ee5f80a:

    irq: call __irq_enter() before calling the tick_idle_check
    Impact: avoid spurious ksoftirqd wakeups

Moving tick_check_idle() before __irq_enter and wrapping it with
local_bh_enable/disable would solve both the problems.

Fixed-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-9-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:29 +02:00
Venkatesh Pallipadi aa48380851 sched: Remove irq time from available CPU power
The idea was suggested by Peter Zijlstra here:

  http://marc.info/?l=linux-kernel&m=127476934517534&w=2

irq time is technically not available to the tasks running on the CPU.
This patch removes irq time from CPU power piggybacking on
sched_rt_avg_update().

Tested this by keeping CPU X busy with a network intensive task having 75%
oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven
cycle soakers on the system. Without this change, there will be two tasks on
each CPU. With this change, there is a single task on irq busy CPU X and
remaining 7 tasks are spread around among other 3 CPUs.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:27 +02:00
Venkatesh Pallipadi 305e6835e0 sched: Do not account irq time to current task
Scheduler accounts both softirq and interrupt processing times to the
currently running task. This means, if the interrupt processing was
for some other task in the system, then the current task ends up being
penalized as it gets shorter runtime than otherwise.

Change sched task accounting to acoount only actual task time from
currently running task. Now update_curr(), modifies the delta_exec to
depend on rq->clock_task.

Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can
extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats
for later.

This change will impact scheduling behavior in interrupt heavy conditions.

Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy
task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2
spending 75%+ of its time in irq processing. CPU 3 spending around 35%
time running nc task.

Now, if I run another CPU intensive task on CPU 2, without this change
/proc/<pid>/schedstat shows 100% of time accounted to this task. With this
change, it rightly shows less than 25% accounted to this task as remaining
time is actually spent on irq processing.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:26 +02:00
Venkatesh Pallipadi b52bfee445 sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time
s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does
the fine granularity accounting of user, system, hardirq, softirq times.
Adding that option on archs like x86 will be challenging however, given the
state of TSC reliability on various platforms and also the overhead it will
add in syscall entry exit.

Instead, add a lighter variant that only does finer accounting of
hardirq and softirq times, providing precise irq times (instead of timer tick
based samples). This accounting is added with a new config option
CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not
interested in paying the perf penalty.

This accounting is based on sched_clock, with the code being generic.
So, other archs may find it useful as well.

This patch just adds the core logic and does not enable this logic yet.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:24 +02:00
Venkatesh Pallipadi 6cdd5199da sched: Add a PF flag for ksoftirqd identification
To account softirq time cleanly in scheduler, we need to identify whether
softirq is invoked in ksoftirqd context or softirq at hardirq tail context.
Add PF_KSOFTIRQD for that purpose.

As all PF flag bits are currently taken, create space by moving one of the
infrequently used bits (PF_THREAD_BOUND) down in task_struct to be along
with some other state fields.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-4-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:22 +02:00
Venkatesh Pallipadi 75e1056f5c sched: Fix softirq time accounting
Peter Zijlstra found a bug in the way softirq time is accounted in
VIRT_CPU_ACCOUNTING on this thread:

   http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html

The problem is, softirq processing uses local_bh_disable internally. There
is no way, later in the flow, to differentiate between whether softirq is
being processed or is it just that bh has been disabled. So, a hardirq when bh
is disabled results in time being wrongly accounted as softirq.

Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING
as well. As account_system_time() in normal tick based accouting also uses
softirq_count, which will be set even when not in softirq with bh disabled.

Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count
for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq
processing. The patch below does that and adds API in_serving_softirq() which
returns whether we are currently processing softirq or not.

Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c
to in_serving_softirq.

Looks like many usages of in_softirq really want in_serving_softirq. Those
changes can be made individually on a case by case basis.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:20 +02:00
Nikhil Rao 75dd321d79 sched: Drop group_capacity to 1 only if local group has extra capacity
When SD_PREFER_SIBLING is set on a sched domain, drop group_capacity to 1
only if the local group has extra capacity. The extra check prevents the case
where you always pull from the heaviest group when it is already under-utilized
(possible with a large weight task outweighs the tasks on the system).

For example, consider a 16-cpu quad-core quad-socket machine with MC and NUMA
scheduling domains. Let's say we spawn 15 nice0 tasks and one nice-15 task,
and each task is running on one core. In this case, we observe the following
events when balancing at the NUMA domain:

- find_busiest_group() will always pick the sched group containing the niced
  task to be the busiest group.
- find_busiest_queue() will then always pick one of the cpus running the
  nice0 task (never picks the cpu with the nice -15 task since
  weighted_cpuload > imbalance).
- The load balancer fails to migrate the task since it is the running task
  and increments sd->nr_balance_failed.
- It repeats the above steps a few more times until sd->nr_balance_failed > 5,
  at which point it kicks off the active load balancer, wakes up the migration
  thread and kicks the nice 0 task off the cpu.

The load balancer doesn't stop until we kick out all nice 0 tasks from
the sched group, leaving you with 3 idle cpus and one cpu running the
nice -15 task.

When balancing at the NUMA domain, we drop sgs.group_capacity to 1 if the child
domain (in this case MC) has SD_PREFER_SIBLING set.  Subsequent load checks are
not relevant because the niced task has a very large weight.

In this patch, we add an extra condition to the "if(prefer_sibling)" check in
update_sd_lb_stats(). We drop the capacity of a group only if the local group
has extra capacity, ie. nr_running < group_capacity. This patch preserves the
original intent of the prefer_siblings check (to spread tasks across the system
in low utilization scenarios) and fixes the case above.

It helps in the following ways:
- In low utilization cases (where nr_tasks << nr_cpus), we still drop
  group_capacity down to 1 if we prefer siblings.
- On very busy systems (where nr_tasks >> nr_cpus), sgs.nr_running will most
  likely be > sgs.group_capacity.
- When balancing large weight tasks, if the local group does not have extra
  capacity, we do not pick the group with the niced task as the busiest group.
  This prevents failed balances, active migration and the under-utilization
  described above.

Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287173550-30365-5-git-send-email-ncrao@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:19 +02:00
Nikhil Rao fab476228b sched: Force balancing on newidle balance if local group has capacity
This patch forces a load balance on a newly idle cpu when the local group has
extra capacity and the busiest group does not have any. It improves system
utilization when balancing tasks with a large weight differential.

Under certain situations, such as a niced down task (i.e. nice = -15) in the
presence of nr_cpus NICE0 tasks, the niced task lands on a sched group and
kicks away other tasks because of its large weight. This leads to sub-optimal
utilization of the machine. Even though the sched group has capacity, it does
not pull tasks because sds.this_load >> sds.max_load, and f_b_g() returns NULL.

With this patch, if the local group has extra capacity, we shortcut the checks
in f_b_g() and try to pull a task over. A sched group has extra capacity if the
group capacity is greater than the number of running tasks in that group.

Thanks to Mike Galbraith for discussions leading to this patch and for the
insight to reuse SD_NEWIDLE_BALANCE.

Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287173550-30365-4-git-send-email-ncrao@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:18 +02:00
Nikhil Rao 2582f0eba5 sched: Set group_imb only a task can be pulled from the busiest cpu
When cycling through sched groups to determine the busiest group, set
group_imb only if the busiest cpu has more than 1 runnable task. This patch
fixes the case where two cpus in a group have one runnable task each, but there
is a large weight differential between these two tasks. The load balancer is
unable to migrate any task from this group, and hence do not consider this
group to be imbalanced.

Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286996978-7007-3-git-send-email-ncrao@google.com>
[ small code readability edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:17 +02:00
Nikhil Rao ef8002f684 sched: Do not consider SCHED_IDLE tasks to be cache hot
This patch adds a check in task_hot to return if the task has SCHED_IDLE
policy. SCHED_IDLE tasks have very low weight, and when run with regular
workloads, are typically scheduled many milliseconds apart. There is no
need to consider these tasks hot for load balancing.

Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287173550-30365-2-git-send-email-ncrao@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 20:52:15 +02:00
Peter Zijlstra 7e54a5a0b6 perf: Optimize sw events
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:59 +02:00
Peter Zijlstra 82cd6def98 perf: Use jump_labels to optimize the scheduler hooks
Trades a call + conditional + ret for an unconditional jmp.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.501657727@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:58 +02:00
Peter Zijlstra 3b6e901f83 jump_label: Use more consistent naming
Now that there's still only a few users around, rename things to make
them more consistent.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.448565169@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:56 +02:00
Peter Zijlstra d580ff8699 perf, hw_breakpoint: Fix crash in hw_breakpoint creation
hw_breakpoint creation needs to account stuff per-task to ensure there
is always sufficient hardware resources to back these things due to
ptrace.

With the perf per pmu context changes the event initialization no
longer has access to the event context, for the simple reason that we
need to first find the pmu (result of initialization) before we can
find the context.

This makes hw_breakpoints unhappy, because it can no longer do per
task accounting, cure this by frobbing a task pointer in the event::hw
bits for now...

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101014203625.391543667@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:55 +02:00
Peter Zijlstra c6be5a5cb6 perf: Find task before event alloc
So that we can pass the task pointer to the event allocation, so that
we can use task associated data during event initialization.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.340789919@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:54 +02:00
Peter Zijlstra e7d0bc0475 perf: Fix task refcount bugs
Currently it looks like find_lively_task_by_vpid() takes a task ref
and relies on find_get_context() to drop it.

The problem is that perf_event_create_kernel_counter() shouldn't be
dropping task refs.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
LKML-Reference: <20101014203625.278436085@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:52 +02:00
Peter Zijlstra 74c3337c2f perf: Fix group moving
Matt found we trigger the WARN_ON_ONCE() in perf_group_attach() when we take
the move_group path in perf_event_open().

Since we cannot de-construct the group (we rely on it to move the events), we
have to simply ignore the double attach. The group state is context invariant
and doesn't need changing.

Reported-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287135757.29097.1368.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:51 +02:00
Peter Zijlstra e360adbe29 irq_work: Add generic hardirq context callbacks
Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:50 +02:00
Stephane Eranian 8e5fc1a732 perf_events: Fix transaction recovery in group_sched_in()
The group_sched_in() function uses a transactional approach to schedule
a group of events. In a group, either all events can be scheduled or
none are. To schedule each event in, the function calls event_sched_in().
In case of error, event_sched_out() is called on each event in the group.

The problem is that event_sched_out() does not completely cancel the
effects of event_sched_in(). Furthermore event_sched_out() changes the
state of the event as if it had run which is not true is this particular
case.

Those inconsistencies impact time tracking fields and may lead to events
in a group not all reporting the same time_enabled and time_running values.
This is demonstrated with the example below:

$ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5
1946101 unhalted_core_cycles (32.85% scaling, ena=829181, run=556827)
  11423 baclears (32.85% scaling, ena=829181, run=556827)
   7671 baclears (0.00% scaling, ena=556827, run=556827)

2250443 unhalted_core_cycles (57.83% scaling, ena=962822, run=405995)
  11705 baclears (57.83% scaling, ena=962822, run=405995)
  11705 baclears (57.83% scaling, ena=962822, run=405995)

Notice that in the first group, the last baclears event does not
report the same timings as its siblings.

This issue comes from the fact that tstamp_stopped is updated
by event_sched_out() as if the event had actually run.

To solve the issue, we must ensure that, in case of error, there is
no change in the event state whatsoever. That means timings must
remain as they were when entering group_sched_in().

To do this we defer updating tstamp_running until we know the
transaction succeeded. Therefore, we have split event_sched_in()
in two parts separating the update to tstamp_running.

Similarly, in case of error, we do not want to update tstamp_stopped.
Therefore, we have split event_sched_out() in two parts separating
the update to tstamp_stopped.

With this patch, we now get the following output:

$ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5
2492050 unhalted_core_cycles (71.75% scaling, ena=1093330, run=308841)
  11243 baclears (71.75% scaling, ena=1093330, run=308841)
  11243 baclears (71.75% scaling, ena=1093330, run=308841)

1852746 unhalted_core_cycles (0.00% scaling, ena=784489, run=784489)
   9253 baclears (0.00% scaling, ena=784489, run=784489)
   9253 baclears (0.00% scaling, ena=784489, run=784489)

Note that the uneven timing between groups is a side effect of
the process spending most of its time sleeping, i.e., not enough
event rotations (but that's a separate issue).

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cb86b4c.41e9d80a.44e9.3e19@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:49 +02:00
Stephane Eranian c530ccd9a1 perf_events: Fix bogus context time tracking
You can only call update_context_time() when the context
is active, i.e., the thread it is attached to is still running.

However, perf_event_read() can be called even when the context
is inactive, e.g., user read() the counters. The call to
update_context_time() must be conditioned on the status of
the context, otherwise, bogus time_enabled, time_running may
be returned. Here is an example on AMD64. The task program
is an example from libpfm4. The -p prints deltas every 1s.

$ task -p -e cpu_clk_unhalted sleep 5
    2,266,610 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
5,242,358,071 cpu_clk_unhalted (99.95% scaling, ena=5,000,359,984, run=2,319,270)

Whereas if you don't read deltas, e.g., no call to perf_event_read() until
the process terminates:

$ task -e cpu_clk_unhalted sleep 5
    2,497,783 cpu_clk_unhalted (0.00% scaling, ena=2,376,899, run=2,376,899)

Notice that time_enable, time_running are bogus in the first example
causing bogus scaling.

This patch fixes the problem, by conditionally calling update_context_time()
in perf_event_read().

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <4cb856dc.51edd80a.5ae0.38fb@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 19:58:46 +02:00
Hitoshi Mitake 4ba053c04a lockdep: Check the depth of subclass
Current look_up_lock_class() doesn't check the parameter "subclass".
This rarely rises problems because the main caller of this function,
register_lock_class(), checks it.

But register_lock_class() is not the only function which calls
look_up_lock_class(). lock_set_class() and its callees also call it.
And lock_set_class() doesn't check this parameter.

This will rise problems when the the value of subclass is larger than
MAX_LOCKDEP_SUBCLASSES. Because the address (used as the key of class)
caliculated with too large subclass has a probability to point
another key in different lock_class_key.

Of course this problem depends on the memory layout and
occurs with really low probability.

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Vojtech Pavlik <vojtech@ucw.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286958626-986-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:44:26 +02:00
Hitoshi Mitake 620162505e lockdep: Add improved subclass caching
Current lockdep_map only caches one class with subclass == 0,
and looks up hash table of classes when subclass != 0.

It seems that this has no problem because the case of
subclass != 0 is rare. But locks of struct rq are
acquired with subclass == 1 when task migration is executed.
Task migration is high frequent event, so I modified lockdep
to cache subclasses.

I measured the score of perf bench sched messaging.
This patch has slightly but certain (order of milli seconds
or 10 milli seconds) effect when lots of tasks are running.
I'll show the result in the tail of this description.

NR_LOCKDEP_CACHING_CLASSES specifies how many classes can be
cached in the instances of lockdep_map.
I discussed with Peter Zijlstra in LinuxCon Japan about
this approach and he taught me that caching every subclasses(8)
is cleary waste of memory. So number of cached classes
should be configurable.

=== Score comparison of benchmarks ===
# "min" means best score, and "max" means worst score

for i in `seq 1 10`; do ./perf bench -f simple sched messaging; done

before: min: 0.565000, max: 0.583000, avg: 0.572500
after:  min: 0.559000, max: 0.568000, avg: 0.563300

# with more processes
for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done

before: min: 2.274000, max: 2.298000, avg: 2.286300
after:  min: 2.242000, max: 2.270000, avg: 2.259700

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286269311-28336-2-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:44:25 +02:00
Ingo Molnar f2f108eb45 Merge branch 'linus' into core/locking
Merge reason: Update to almost-final-.36

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:43:46 +02:00
Linus Walleij 17bdcf949d sched: Drop all load weight manipulation for RT tasks
Load weights are for the CFS, they do not belong in the RT task. This makes all
RT scheduling classes leave the CFS weights alone.

This fixes a real bug as well: I noticed the following phonomena: a process
elevated to SCHED_RR forks with SCHED_RESET_ON_FORK set, and the child is
indeed SCHED_OTHER, and the niceval is indeed reset to 0. However the weight
inserted by set_load_weight() remains at 0, giving the task insignificat
priority.

With this fix, the weight is reset to what the task had before being elevated
to SCHED_RR/SCHED_FIFO.

Cc: Lennart Poettering <lennart@poettering.net>
Cc: stable@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286807811-10568-1-git-send-email-linus.walleij@stericsson.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:41:59 +02:00
Peter Zijlstra 34f971f6f7 sched: Create special class for stop/migrate work
In order to separate the stop/migrate work thread from the SCHED_FIFO
implementation, create a special class for it that is of higher priority than
SCHED_FIFO itself.

This currently solves a problem where cpu-hotplug consumes so much cpu-time
that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment
timer pending on the now dead cpu.

It is also required for when we add the planned deadline scheduling class above
SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks.

Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1285165776.2275.1022.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:41:58 +02:00
Peter Zijlstra 4924627423 sched: Unindent labels
Labels should be on column 0.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:41:56 +02:00
Steven Rostedt 78c89ba121 tracing: Remove parent recording in latency tracer graph options
Even though the parent is recorded with the normal function tracing
of the latency tracers (irqsoff and wakeup), the function graph
recording is bogus.

This is due to the function graph messing with the return stack.
The latency tracers pass in as the parent CALLER_ADDR0, which
works fine for plain function tracing. But this causes bogus output
with the graph tracer:

 3)    <idle>-0    |  d.s3.  0.000 us    |  return_to_handler();
 3)    <idle>-0    |  d.s3.  0.000 us    |  _raw_spin_unlock_irqrestore();
 3)    <idle>-0    |  d.s3.  0.000 us    |  return_to_handler();
 3)    <idle>-0    |  d.s3.  0.000 us    |  trace_hardirqs_on();

The "return_to_handle()" call is the trampoline of the
function graph tracer, and is meaningless in this context.

Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:38 -04:00
Steven Rostedt 5e6d2b9cfa tracing: Use one prologue for the preempt irqs off tracer function tracers
The preempt and irqsoff tracers have three types of function tracers.
Normal function tracer, function graph entry, and function graph return.
Each of these use a complex dance to prevent recursion and whether
to trace the data or not (depending if interrupts are enabled or not).

This patch moves the duplicate code into a single routine, to
prevent future mistakes with modifying duplicate complex code.

Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:36 -04:00
Steven Rostedt 542181d376 tracing: Use one prologue for the wakeup tracer function tracers
The wakeup tracer has three types of function tracers. Normal
function tracer, function graph entry, and function graph return.
Each of these use a complex dance to prevent recursion and whether
to trace the data or not (depending on the wake_task variable).

This patch moves the duplicate code into a single routine, to
prevent future mistakes with modifying duplicate complex code.

Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:33 -04:00
Jiri Olsa 7495a5beaa tracing: Graph support for wakeup tracer
Add function graph support for wakeup latency tracer.
The graph output is enabled by setting the 'display-graph'
trace option.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1285243253-7372-4-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:30 -04:00
Jiri Olsa 0a772620a2 tracing: Make graph related irqs/preemptsoff functions global
Move trace_graph_function() and print_graph_headers_flags() functions
to the trace_function_graph.c to be globaly available.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1285243253-7372-3-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:28 -04:00
Jiri Olsa a9d61173dc tracing: Add proper check for irq_depth routines
The check_irq_entry and check_irq_return could be called
from graph event context. In such case there's no graph
private data allocated. Adding checks to handle this case.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <20100924154102.GB1818@jolsa.brq.redhat.com>

[ Fixed some grammar in the comments ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:25 -04:00
matt mooney 907f278409 tracing/trivial: Remove cast from void*
Unnecessary cast from void* in assignment.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-18 10:53:22 -04:00
Nishanth Menon e1f60b292f PM: Introduce library for device-specific OPPs (v7)
SoCs have a standard set of tuples consisting of frequency and
voltage pairs that the device will support per voltage domain. These
are called Operating Performance Points or OPPs. The actual
definitions of OPP varies over silicon versions. For a specific domain,
we can have a set of {frequency, voltage} pairs. As the kernel boots
and more information is available, a default set of these are activated
based on the precise nature of device. Further on operation, based on
conditions prevailing in the system (such as temperature), some OPP
availability may be temporarily controlled by the SoC frameworks.

To implement an OPP, some sort of power management support is necessary
hence this library depends on CONFIG_PM.

Contributions include:
Sanjeev Premi for the initial concept:
	http://patchwork.kernel.org/patch/50998/
Kevin Hilman for converting original design to device-based.
Kevin Hilman and Paul Walmsey for cleaning up many of the function
abstractions, improvements and data structure handling.
Romit Dasgupta for using enums instead of opp pointers.
Thara Gopinath, Eduardo Valentin and Vishwanath BS for fixes and
cleanups.
Linus Walleij for recommending this layer be made generic for usage
in other architectures beyond OMAP and ARM.
Mark Brown, Andrew Morton, Rafael J. Wysocki, Paul E. McKenney for
valuable improvements.

Discussions and comments from:
http://marc.info/?l=linux-omap&m=126033945313269&w=2
http://marc.info/?l=linux-omap&m=125482970102327&w=2
http://marc.info/?t=125809247500002&r=1&w=2
http://marc.info/?l=linux-omap&m=126025973426007&w=2
http://marc.info/?t=128152609200064&r=1&w=2
http://marc.info/?t=128468723000002&r=1&w=2
incorporated.

v1: http://marc.info/?t=128468723000002&r=1&w=2

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:50 +02:00
James Hogan d33ac60bea PM: Add sysfs attr for rechecking dev hash from PM trace
If the device which fails to resume is part of a loadable kernel module
it won't be checked at startup against the magic number stored in the
RTC.

Add a read-only sysfs attribute /sys/power/pm_trace_dev_match which
contains a list of newline separated devices (usually just the one)
which currently match the last magic number. This allows the device
which is failing to resume to be found after the modules are loaded
again.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:50 +02:00
Rafael J. Wysocki 3624eb04c2 PM / Hibernate: Modify signature used to mark swap
Since we are adding compression to the kernel's hibernate code,
change signature used by it to mark swap spaces, so that earlier
kernels don't attempt to restore compressed images they cannot
handle.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
2010-10-17 01:57:49 +02:00
Rafael J. Wysocki dbeeec5fe8 PM: Allow wakeup events to abort freezing of tasks
If there is a wakeup event during the freezing of tasks, suspend or
hibernation will fail anyway.  Since try_to_freeze_tasks() can take
up to 20 seconds to complete or fail, aborting it as soon as a wakeup
event is detected improves the worst case wakeup latency.

Based on a patch from Arve Hjønnevåg.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
2010-10-17 01:57:49 +02:00
Rafael J. Wysocki d0941ead3f PM / Hibernate: Make some boot messages look less scary
The hibernate resume code checks if there is an image to resume from
on every boot and, if the kernel is built with CONFIG_PM_DEBUG set
and the image is not present, it prints some scary messages
suggesting there was a boot error of some sort.  Apparently, some
users are confused by them, so make them look less scary and adjust
the other hibernate resume debug messages to match them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:48 +02:00
Rafael J. Wysocki 074037ec79 PM / Wakeup: Introduce wakeup source objects and event statistics (v3)
Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet).  Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.

Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-17 01:57:43 +02:00
Rafael J. Wysocki ac5c24ec1e PM / Hibernate: Make default image size depend on total RAM size
The default hibernation image size is currently hard coded and euqal
to 500 MB, which is not a reasonable default on many contemporary
systems.  Make it equal 2/5 of the total RAM size (this is slightly
below the maximum, i.e. 1/2 of the total RAM size, and seems to be
generally suitable).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: M. Vefa Bicakci <bicave@superonline.com>
2010-10-17 01:57:43 +02:00
Rafael J. Wysocki 266f1a25ef PM / Hibernate: Improve comments in hibernate_preallocate_memory()
One comment in hibernate_preallocate_memory() is wrong, so fix it and
add one more comment to clarify the meaning of the fixed one.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:42 +02:00
Rafael J. Wysocki bcb5ba8b4e PM / Runtime: Use alloc_workqueue() for creating the PM workqueue
Although we need the PM workqueue to be freezable, we don't need it
to be singlethread.  Also, the number of concurrent work items
running on a single CPU need not be constrained.  For these reasons
use alloc_workqueue() directly, with suitable arguments, instead of
create_freezeable_workqueue(), to create the runtime PM workqueue.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Tejun Heo <tj@kernel.org>
2010-10-17 01:57:42 +02:00
Rafael J. Wysocki ede890c2c0 PM: Fix unmet dependency warning from kconfig
Fix the following build warning:

warning: (PM_SLEEP_SMP && SMP && (ARCH_SUSPEND_POSSIBLE || \
ARCH_HIBERNATION_POSSIBLE) && PM_SLEEP) selects HOTPLUG_CPU which \
has unmet direct dependencies (SMP && HOTPLUG)

by selecting HOTPLUG along with CPU_HOTPLUG.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
2010-10-17 01:57:42 +02:00
Bojan Smojver f996fc9671 PM / Hibernate: Compress hibernation image with LZO
Compress hibernation image with LZO in order to save on I/O and
therefore time to hibernate/thaw.

[rjw: Added hibernate=nocompress command line option instead of just
 nocompress which would be confusing, fixed a couple of compiler
 warnings, fixed kerneldoc comments, minor cleanups.]

Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:42 +02:00
Eric Dumazet a9febbb4bd sysctl: min/max bounds are optional
sysctl check complains with a WARN() when proc_doulongvec_minmax() or
proc_doulongvec_ms_jiffies_minmax() are used by a vector of longs (with
more than one element), with no min or max value specified.

This is unexpected, given we had a bug on this min/max handling :)

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-15 14:42:24 -07:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Robert Richter 6268464b37 Merge remote branch 'tip/perf/core' into oprofile/core
Conflicts:
	arch/arm/oprofile/common.c
	kernel/perf_event.c
2010-10-15 12:45:00 +02:00
Ingo Molnar 0fdf13606b Merge branch 'tip/perf/recordmcount-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-10-15 06:12:28 +02:00
Steven Rostedt cf4db2597a ftrace: Rename config option HAVE_C_MCOUNT_RECORD to HAVE_C_RECORDMCOUNT
The config option used by archs to let the build system know that
the C version of the recordmcount works for said arch is currently
called HAVE_C_MCOUNT_RECORD which enables BUILD_C_RECORDMCOUNT. To
be more consistent with the name that all archs may use, it has been
renamed to HAVE_C_RECORDMCOUNT. This will be less confusing since
we are building a C recordmcount and not a mcount_record.

Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Cc: John Reiser <jreiser@bitwagon.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-14 23:32:44 -04:00
Ingo Molnar d9d572a9c0 Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-10-15 05:12:45 +02:00
Steven Rostedt 72441cb1fd ftrace/x86: Add support for C version of recordmcount
This patch adds the support for the C version of recordmcount and
compile times show ~ 12% improvement.

After verifying this works, other archs can add:

 HAVE_C_MCOUNT_RECORD

in its Kconfig and it will use the C version of recordmcount
instead of the perl version.

Cc: <linux-arch@vger.kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Cc: John Reiser <jreiser@bitwagon.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-14 16:52:41 -04:00
Salman Qazi f13d4f979c hrtimer: Preserve timer state in remove_hrtimer()
The race is described as follows:

CPU X                                 CPU Y
remove_hrtimer
// state & QUEUED == 0
timer->state = CALLBACK
unlock timer base
timer->f(n) //very long
                                  hrtimer_start
                                    lock timer base
                                    remove_hrtimer // no effect
                                    hrtimer_enqueue
                                    timer->state = CALLBACK |
                                                   QUEUED
                                    unlock timer base
                                  hrtimer_start
                                    lock timer base
                                    remove_hrtimer
                                        mode = INACTIVE
                                        // CALLBACK bit lost!
                                    switch_hrtimer_base
                                            CALLBACK bit not set:
                                                    timer->base
                                                    changes to a
                                                    different CPU.
lock this CPU's timer base

The bug was introduced with commit ca109491f (hrtimer: removing all ur
callback modes) in 2.6.29

[ tglx: Feed new state via local variable and add a comment. ]

Signed-off-by: Salman Qazi <sqazi@google.com>
Cc: akpm@linux-foundation.org
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20101012142351.8485.21823.stgit@dungbeetle.mtv.corp.google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2010-10-14 13:29:59 +02:00
Takuya Yoshikawa 864616ee67 sched: Comment updates: fix default latency and granularity numbers
Targeted preemption latency and minimal preemption granularity
for CPU-bound tasks have been changed.

This patch updates the comments about these values.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20101014160913.eb24fef4.yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 09:13:35 +02:00
Ingo Molnar ed859ed3b0 Merge branch 'linus' into sched/core
Merge reason: update from -rc5 to -almost-final

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 09:11:46 +02:00
Randy Dunlap fb62db2ba9 futex: Fix kernel-doc notation & typos
Convert futex_requeue() function parameters to use @name
kernel-doc notation and add @fshared & @cmpval to prevent
kernel-doc warnings.

Add @list to struct futex_q.

Fix a few typos.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20101013110234.89b06043.randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:57:35 +02:00
Masami Hiramatsu fd02e6f7ae kprobes: Fix selftest to clear flags field for reusing probes
Fix selftest to clear flags field for reusing probes
because the flags field can be modified by Kprobes.
This also set NULL to kprobe.addr instead of 0.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101014031024.4100.50107.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:55:27 +02:00
Borislav Petkov 14cae9bd2f tracing: Fix function-graph build warning on 32-bit
Fix

kernel/trace/trace_functions_graph.c: In function ‘trace_print_graph_duration’:
kernel/trace/trace_functions_graph.c:652: warning: comparison of distinct pointer types lacks a cast

when building 36-rc6 on a 32-bit due to the strict type check failing
in the min() macro.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100929080823.GA13595@liondog.tnic>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-10-13 17:47:53 +02:00
Benjamin Herrenschmidt 4783f393de Merge remote branch 'kumar/merge' into next 2010-10-13 16:18:36 +11:00
Thomas Gleixner c0a19ebc01 genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build
This option can be set to verify the full conversion to the new chip
functions. Fix the fallout of the patch rework, so the core code
compiles and works with it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12 21:59:55 +02:00
Steven Rostedt d01343244a ring-buffer: Fix typo of time extends per page
Time stamps for the ring buffer are created by the difference between
two events. Each page of the ring buffer holds a full 64 bit timestamp.
Each event has a 27 bit delta stamp from the last event. The unit of time
is nanoseconds, so 27 bits can hold ~134 milliseconds. If two events
happen more than 134 milliseconds apart, a time extend is inserted
to add more bits for the delta. The time extend has 59 bits, which
is good for ~18 years.

Currently the time extend is committed separately from the event.
If an event is discarded before it is committed, due to filtering,
the time extend still exists. If all events are being filtered, then
after ~134 milliseconds a new time extend will be added to the buffer.

This can only happen till the end of the page. Since each page holds
a full timestamp, there is no reason to add a time extend to the
beginning of a page. Time extends can only fill a page that has actual
data at the beginning, so there is no fear that time extends will fill
more than a page without any data.

When reading an event, a loop is made to skip over time extends
since they are only used to maintain the time stamp and are never
given to the caller. As a paranoid check to prevent the loop running
forever, with the knowledge that time extends may only fill a page,
a check is made that tests the iteration of the loop, and if the
iteration is more than the number of time extends that can fit in a page
a warning is printed and the ring buffer is disabled (all of ftrace
is also disabled with it).

There is another event type that is called a TIMESTAMP which can
hold 64 bits of data in the theoretical case that two events happen
18 years apart. This code has not been implemented, but the name
of this event exists, as well as the structure for it. The
size of a TIMESTAMP is 16 bytes, where as a time extend is only
8 bytes. The macro used to calculate how many time extends can fit on
a page used the TIMESTAMP size instead of the time extend size
cutting the amount in half.

The following test case can easily trigger the warning since we only
need to have half the page filled with time extends to trigger the
warning:

 # cd /sys/kernel/debug/tracing/
 # echo function > current_tracer
 # echo 'common_pid < 0' > events/ftrace/function/filter
 # echo > trace
 # echo 1 > trace_marker
 # sleep 120
 # cat trace

Enabling the function tracer and then setting the filter to only trace
functions where the process id is negative (no events), then clearing
the trace buffer to ensure that we have nothing in the buffer,
then write to trace_marker to add an event to the beginning of a page,
sleep for 2 minutes (only 35 seconds is probably needed, but this
guarantees the bug), and then finally reading the trace which will
trigger the bug.

This patch fixes the typo and prevents the false positive of that warning.

Reported-by: Hans J. Koch <hjk@linutronix.de>
Tested-by: Hans J. Koch <hjk@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-12 12:06:43 -04:00
Thomas Gleixner 5b8c4f23c5 printk: Make console_sem a semaphore not a pseudo mutex
It needs to be investigated whether it can be replaced by a real
mutex, but that needs more thought.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125057.179587334@linutronix.de>
2010-10-12 17:36:10 +02:00
Thomas Gleixner 37eca0d64a Merge branch 'linus' into core/locking
Reason: Pull in the semaphore related changes

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12 17:27:28 +02:00
Thomas Gleixner baa0d233af genirq: Switch sparse_irq allocator to GFP_KERNEL
The allocator functions are now called outside of preempt disabled
regions. Switch to GFP_KERNEL.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:45 +02:00
Thomas Gleixner a05a900a51 genirq: Make sparse_lock a mutex
No callers from atomic regions. 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:45 +02:00
Thomas Gleixner 78f90d91f3 genirq: Remove the now unused sparse irq leftovers
The move_irq_desc() function was only used due to the problem that the
allocator did not free the old descriptors. So the descriptors had to
be moved in create_irq_nr(). That's history.

The code would have never been able to move active interrupt
descriptors on affinity settings. That can be done in a completely
different way w/o all this horror.

Remove all of it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:44 +02:00
Thomas Gleixner b7b29338dc genirq: Sanitize dynamic irq handling
Use the cleanup functions of the dynamic allocator. No need to have
separate implementations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:44 +02:00
Thomas Gleixner b7d0d8258a genirq: Remove arch_init_chip_data()
This function should have not been there in the first place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:44 +02:00
Thomas Gleixner 7c5f13519a Merge branch 'x86/urgent' of into irq/sparseirq
Reason: Pull in the latest io_apic bugfixes

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12 16:41:26 +02:00
Thomas Gleixner b683de2b3c genirq: Query arch for number of early descriptors
sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go
ahead and allocate more.

Use the unused return value of arch_probe_nr_irqs() to let the
architecture return the number of early allocations. Fix up all users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:08 +02:00
Thomas Gleixner aa99ec0f3f genirq: Use sane sparse allocator
Make irq_to_desc_alloc_node() a wrapper around the new allocator.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 06f6c3399e genirq: Implement irq reservation
Mark a range of interrupts as allocated. In the SPARSE_IRQ=n case we
need this to update the bitmap for the legacy irqs so the enumerator
via irq_get_next_irq() works.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12 16:39:07 +02:00
Thomas Gleixner a98d24b71b genirq: Implement sane enumeration
Use the allocator bitmap to lookup active interrupts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 13bfe99e09 genirq: Prepare proc for real sparse irq support
/proc/irq never removes any entries, but when irq descriptors can be
freed for real this is necessary. Otherwise we'd reference a freed
descriptor in /proc/irq/N

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 1f5a5b87f7 genirq: Implement a sane sparse_irq allocator
The current sparse_irq allocator has several short comings due to
failures in the design or the lack of it:

 - Requires iteration over the number of active irqs to find a free slot
   (Some architectures have grown their own workarounds for this)
 - Removal of entries is not possible
 - Racy between create_irq_nr and destroy_irq (plugged by horrible
   callbacks)
 - Migration of active irq descriptors is not possible
 - No bulk allocation of irq ranges
 - Sprinkeled irq_desc references all over the place outside of kernel/irq/
   (The previous chip functions series is addressing this issue)

Implement a sane allocator which fixes the above short comings (though
migration of active descriptors needs a full tree wide cleanup of the
direct and mostly unlocked access to irq_desc).

The new allocator still uses a radix_tree, but uses a bitmap for
keeping track of allocated irq numbers. That allows:

 - Fast lookup of a free slot
 - Allows the removal of descriptors
 - Prevents the create/destroy race
 - Bulk allocation of consecutive irq ranges
 - Basic design is ready for migration of life descriptors after
   further cleanups

The bitmap is also used in the SPARSE_IRQ=n case for lookup and
raceless (de)allocation of irq numbers. So it removes the requirement
for looping through the descriptor array to find slots.

Right now it uses sparse_irq_lock to protect the bitmap and the radix
tree, but after cleaning up all users we should be able convert that
to a mutex and to switch the radix_tree and decriptor allocations to
GFP_KERNEL.

[ Folded in a bugfix from Yinghai Lu ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 1318a481fc genirq: Provide default irq init flags
Arch code sets it's own irq_desc.status flags right after boot and for
dynamically allocated interrupts. That might involve iterating over a
huge array.

Allow ARCH_IRQ_INIT_FLAGS to set separate flags aside of IRQ_DISABLED
which is the default.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:06 +02:00
Thomas Gleixner d895f51ebb genirq: Remove export of kstat_irqs_cpu
The statistics accessor is only used by proc/stats and
show_interrupts(). Both are compiled in.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:06 +02:00
Thomas Gleixner 154cd387cd genirq: Remove early_init_irq_lock_class()
early_init_irq_lock_class() is called way before anything touches the
irq descriptors. In case of SPARSE_IRQ=y this is a NOP operation
because the radix tree is empty at this point. For the SPARSE_IRQ=n
case it's sufficient to set the lock class in early_init_irq(). 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:06 +02:00
Thomas Gleixner 3795de236d genirq: Distangle kernel/irq/handle.c
kernel/irq/handle.c has become a dumpground for random code in random
order. Split out the irq descriptor management and the dummy irq_chip
implementation into separate files. Cleanup the include maze while at
it.

No code change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:05 +02:00
Thomas Gleixner f303a6dd12 genirq: Sanitize irq_data accessors
Get the data structure from the core and provide inline wrappers to
access the irq_data members.

Provide accessor inlines for irq_data as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:05 +02:00
Thomas Gleixner 442471848f genirq: Provide status modifier
Provide a irq_desc.status modifier function to cleanup the direct
access to irq_desc in arch and driver code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:05 +02:00
Thomas Gleixner e144710b30 genirq: Distangle irq.h
Move irq_desc and internal functions out of irq.h

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:04 +02:00
John Blackwood ad0cf3478d perf: Fix incorrect copy_from_user() usage
perf events: repair incorrect use of copy_from_user

This makes the perf_event_period() return 0 instead of
-EFAULT on success.

Signed-off-by: John Blackwood<john.blackwood@ccur.com>
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100928220311.GA18145@tsunami.ccur.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 11:45:01 +02:00
H. Peter Anvin 8e4029ee35 Merge branch 'x86/urgent' into core/memblock
Reason for merge:

Forward-port urgent change to arch/x86/mm/srat_64.c to the memblock tree.

Resolved Conflicts:
	arch/x86/mm/srat_64.c

Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-11 17:05:11 -07:00
Robert Richter ad0f7cfaa8 Merge branch 'oprofile/urgent' (early part) into oprofile/perf 2010-10-11 19:26:50 +02:00
Matt Fleming 84c7991059 perf: New helper function for pmu name
Introduce perf_pmu_name() helper function that returns the name of the
pmu. This gives us a generic way to get the name of a pmu regardless of
how an architecture identifies it internally.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-10-11 17:45:49 +02:00
Tejun Heo 6370a6ad3b workqueue: add and use WQ_MEM_RECLAIM flag
Add WQ_MEM_RECLAIM flag which currently maps to WQ_RESCUER, mark
WQ_RESCUER as internal and replace all external WQ_RESCUER usages to
WQ_MEM_RECLAIM.

This makes the API users express the intent of the workqueue instead
of indicating the internal mechanism used to guarantee forward
progress.  This is also to make it cleaner to add more semantics to
WQ_MEM_RECLAIM.  For example, if deemed necessary, memory reclaim
workqueues can be made highpri.

This patch doesn't introduce any functional change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
2010-10-11 15:20:26 +02:00
Tejun Heo 30310045dd workqueue: fix HIGHPRI handling in keep_working()
The policy function keep_working() didn't check GCWQ_HIGHPRI_PENDING
and could return %false with highpri work pending.  This could lead to
late execution of a highpri work which was delayed due to @max_active
throttling if other works are actively consuming CPU cycles.

For example, the following could happen.

1. Work W0 which burns CPU cycles.

2. Two works W1 and W2 are queued to a highpri wq w/ @max_active of 1.

3. W1 starts executing and W2 is put to delayed queue.  W0 and W1 are
   both runnable.

4. W1 finishes which puts W2 to pending queue but keep_working()
   incorrectly returns %false and the worker goes to sleep.

5. W0 finishes and W2 starts execution.

With this patch applied, W2 starts execution as soon as W1 finishes.

Signed-off-by: Tejun Heo <tj@kernel.org>
2010-10-11 12:09:30 +02:00
Ingo Molnar 7cd2541cf2 Merge commit 'v2.6.36-rc7' into perf/core
Conflicts:
	arch/x86/kernel/module.c

Merge reason: Resolve the conflict, pick up fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-08 10:46:27 +02:00
Ingo Molnar 153db80f8c Merge commit 'v2.6.36-rc7' into core/memblock
Merge reason: Update from -rc3 to -rc7.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-08 09:15:00 +02:00
Linus Torvalds 6b0cd00bc3 Merge branch 'hwpoison-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
  HWPOISON: Stop shrinking at right page count
  HWPOISON: Report correct address granuality for AO huge page errors
  HWPOISON: Copy si_addr_lsb to user
  page-types.c: fix name of unpoison interface
2010-10-07 13:59:32 -07:00
Eric Dumazet 27b3d80a7b sysctl: fix min/max handling in __do_proc_doulongvec_minmax()
When proc_doulongvec_minmax() is used with an array of longs, and no
min/max check requested (.extra1 or .extra2 being NULL), we dereference a
NULL pointer for the second element of the array.

Noticed while doing some changes in network stack for the "16TB problem"

Fix is to not change min & max pointers in __do_proc_doulongvec_minmax(),
so that all elements of the vector share an unique min/max limit, like
proc_dointvec_minmax().

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-07 13:31:21 -07:00
Peter Zijlstra 6506cf6ce6 sched: fix RCU lockdep splat from task_group()
This addresses the following RCU lockdep splat:

[0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03
[0.052999] lockdep: fixing up alternatives.
[0.054105]
[0.054106] ===================================================
[0.054999] [ INFO: suspicious rcu_dereference_check() usage. ]
[0.054999] ---------------------------------------------------
[0.054999] kernel/sched.c:616 invoked rcu_dereference_check() without protection!
[0.054999]
[0.054999] other info that might help us debug this:
[0.054999]
[0.054999]
[0.054999] rcu_scheduler_active = 1, debug_locks = 1
[0.054999] 3 locks held by swapper/1:
[0.054999]  #0:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff814be933>] cpu_up+0x42/0x6a
[0.054999]  #1:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810400d8>] cpu_hotplug_begin+0x2a/0x51
[0.054999]  #2:  (&rq->lock){-.-...}, at: [<ffffffff814be2f7>] init_idle+0x2f/0x113
[0.054999]
[0.054999] stack backtrace:
[0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1
[0.054999] Call Trace:
[0.054999]  [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3
[0.054999]  [<ffffffff810325c3>] task_group+0x7b/0x8a
[0.054999]  [<ffffffff810325e5>] set_task_rq+0x13/0x40
[0.054999]  [<ffffffff814be39a>] init_idle+0xd2/0x113
[0.054999]  [<ffffffff814be78a>] fork_idle+0xb8/0xc7
[0.054999]  [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b
[0.054999]  [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b
[0.054999]  [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724
[0.054999]  [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b
[0.054999]  [<ffffffff814be876>] _cpu_up+0xac/0x127
[0.054999]  [<ffffffff814be946>] cpu_up+0x55/0x6a
[0.054999]  [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff
[0.054999]  [<ffffffff81003854>] kernel_thread_helper+0x4/0x10
[0.054999]  [<ffffffff814c353c>] ? restore_args+0x0/0x30
[0.054999]  [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff
[0.054999]  [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10
[0.056074] Booting Node   0, Processors  #1lockdep: fixing up alternatives.
[0.130045]  #2lockdep: fixing up alternatives.
[0.203089]  #3 Ok.
[0.275286] Brought up 4 CPUs
[0.276005] Total of 4 processors activated (16017.17 BogoMIPS).

The cgroup_subsys_state structures referenced by idle tasks are never
freed, because the idle tasks should be part of the root cgroup,
which is not removable.

The problem is that while we do in-fact hold rq->lock, the newly spawned
idle thread's cpu is not yet set to the correct cpu so the lockdep check
in task_group():

  lockdep_is_held(&task_rq(p)->lock)

will fail.

But this is a chicken and egg problem.  Setting the CPU's runqueue requires
that the CPU's runqueue already be set.  ;-)

So insert an RCU read-side critical section to avoid the complaint.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-10-07 10:41:07 -07:00
Dongdong Deng 4ee0a60392 rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
Using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
due to the caller didn't hold the root_rcu/rnp node's lock.  Although
use without ACCESS_ONCE() is safe due to the value loaded being used
but once, the ACCESS_ONCE() is a good documentation aid -- the variables
are being loaded without the services of a lock.

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
CC: Dipankar Sarma <dipankar@in.ibm.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-10-07 10:41:06 -07:00
Paul E. McKenney b0a0f667a3 sched: suppress RCU lockdep splat in task_fork_fair
> ===================================================
> [ INFO: suspicious rcu_dereference_check() usage. ]
> ---------------------------------------------------
> /home/greearb/git/linux.wireless-testing/kernel/sched.c:618 invoked rcu_dereference_check() without protection!
>
> other info that might help us debug this:
>
> rcu_scheduler_active = 1, debug_locks = 1
> 1 lock held by ifup/23517:
>   #0:  (&rq->lock){-.-.-.}, at: [<c042f782>] task_fork_fair+0x3b/0x108
>
> stack backtrace:
> Pid: 23517, comm: ifup Not tainted 2.6.36-rc6-wl+ #5
> Call Trace:
>   [<c075e219>] ? printk+0xf/0x16
>   [<c0455842>] lockdep_rcu_dereference+0x74/0x7d
>   [<c0426854>] task_group+0x6d/0x79
>   [<c042686e>] set_task_rq+0xe/0x57
>   [<c042f79e>] task_fork_fair+0x57/0x108
>   [<c042e965>] sched_fork+0x82/0xf9
>   [<c04334b3>] copy_process+0x569/0xe8e
>   [<c0433ef0>] do_fork+0x118/0x262
>   [<c076302f>] ? do_page_fault+0x16a/0x2cf
>   [<c044b80c>] ? up_read+0x16/0x2a
>   [<c04085ae>] sys_clone+0x1b/0x20
>   [<c04030a5>] ptregs_clone+0x15/0x30
>   [<c0402f1c>] ? sysenter_do_call+0x12/0x38

Here a newly created task is having its runqueue assigned.  The new task
is not yet on the tasklist, so cannot go away.  This is therefore a false
positive, suppress with an RCU read-side critical section.

Reported-by: Ben Greear <greearb@candelatech.com
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Ben Greear <greearb@candelatech.com
2010-10-07 10:40:50 -07:00
Ingo Molnar 556ef63255 Merge commit 'v2.6.36-rc7' into core/rcu
Merge reason: Update from -rc3 to -rc7.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-07 09:43:45 +02:00
Ingo Molnar d4f8f217b8 Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu 2010-10-07 09:43:11 +02:00
Andi Kleen a337fdac7a HWPOISON: Copy si_addr_lsb to user
The original hwpoison code added a new siginfo field si_addr_lsb to
pass the granuality of the fault address to user space. Unfortunately
this field was never copied to user space. Fix this here.

I added explicit checks for the MCEERR codes to avoid having
to patch all potential callers to initialize the field.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-10-07 09:41:25 +02:00
Paul E. McKenney 773e3f9357 rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held
As suggested by Linus, push the irqs_disabled() down to the
rcu_read_lock_bh_held() level so that all callers get the benefit
of the correct check.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-10-05 14:03:02 -07:00
Linus Torvalds e1d9694cae Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: rcu_read_lock_bh_held(): disabling irqs also disables bh
  generic-ipi: Fix deadlock in __smp_call_function_single
2010-10-05 13:07:43 -07:00
Linus Torvalds 5336377d62 modules: Fix module_bug_list list corruption race
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.

However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling.  That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.

Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.

So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.

Future fixups:
 - move the module list handling code into kernel/module.c where it
   belongs.
 - get rid of 'module_bug_list' and just use the regular list of modules
   (called 'modules' - imagine that) that we already create and maintain
   for other reasons.

Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-05 11:29:27 -07:00
Tejun Heo cdadf0097c workqueue: add queue_work and activate_work trace points
These two tracepoints allow tracking when and how a work is queued and
activated.  This patch is based on Frederic's patch to add queue_work
trace point.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
2010-10-05 10:49:55 +02:00
Tejun Heo 97bd234701 workqueue: prepare for more tracepoints
Define workqueue_work event class and use it for workqueue_execute_end
trace point.  Also, move trace/events/workqueue.h include downwards
such that all struct definitions are visible to it.  This is to
prepare for more tracepoints and doesn't cause any functional change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
2010-10-05 10:41:14 +02:00
Jan Blunck 38d018dba3 BKL: Remove BKL from cgroup
The BKL is only used in remount_fs and get_sb that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
BKL entirely.

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-10-04 21:10:42 +02:00
Jan Blunck db71922217 BKL: Explicitly add BKL around get_sb/fill_super
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.

do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.

Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.

[arnd: do not add the BKL to those file systems that already
       don't use it elsewhere]

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-04 21:10:10 +02:00
Thomas Gleixner bd15141226 genirq: Provide config option to disable deprecated code
This option covers now the old chip functions and the irq_desc data
fields which are moving to struct irq_data. More stuff will follow.

Pretty handy for testing a conversion, whether something broke or not.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 13:40:24 +02:00
Stephane Eranian 540804b5c5 perf_events: Fix invalid pointer when pid is invalid
This patch fixes an error in perf_event_open() when the pid
provided by the user is invalid. find_lively_task_by_vpid()
does not return NULL on error but an error code. Without the
fix the error code was silently passed to find_get_context()
which would eventually cause a invalid pointer dereference.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: paulus@samba.org
Cc: davem@davemloft.net
Cc: fweisbec@gmail.com
Cc: perfmon2-devel@lists.sf.net
Cc: eranian@gmail.com
Cc: robert.richter@amd.com
LKML-Reference: <4ca9a5d1.e8e9d80a.3dbb.ffff8f2e@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:47:20 +02:00
Thomas Gleixner 21e2b8c62c genirq: Provide compat handling for chip->retrigger()
Wrap the old chip function retrigger() until the migration is complete
and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121843.025801092@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:50 +02:00
Thomas Gleixner 2f7e99bb9b genirq: Provide compat handling for chip->set_wake()
Wrap the old chip function set_wake() until the migration is complete
and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.927527393@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:48 +02:00
Thomas Gleixner b2ba2c3003 genirq: Provide compat handling for chip->set_type()
Wrap the old chip function set_type() until the migration is complete
and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.832261548@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:47 +02:00
Thomas Gleixner c96b3b3c44 genirq: Provide compat handling for chip->set_affinity()
Wrap the old chip function set_affinity() until the migration is
complete and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.732894108@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:46 +02:00
Thomas Gleixner 37e12df709 genirq: Provide compat handling for chip->startup()
Wrap the old chip function startup() until the migration is complete and
the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.635152961@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:44 +02:00
Thomas Gleixner bc310dda41 genirq: Provide compat handling for chip->disable()/shutdown()
Wrap the old chip functions disable() and shutdown() until the
migration is complete and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.532070631@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:43 +02:00
Thomas Gleixner c5f756344c genirq: Provide compat handling for chip->enable()
Wrap the old chip function enable() until the migration is complete and
the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.437159182@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:42 +02:00
Thomas Gleixner 0c5c15572a genirq: Provide compat handling for chip->eoi()
Wrap the old chip function eoi() until the migration is complete and
the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.339657617@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:41 +02:00
Thomas Gleixner 9205e31d1a genirq: Provide compat handling for chip->mask_ack()
Wrap the old chip function mask_ack() until the migration is complete
and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.240806983@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:40 +02:00
Thomas Gleixner 22a49163e9 genirq: Provide compat handling for chip->ack()
Wrap the old chip function ack() until the migration is complete and
the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.142624725@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:38 +02:00
Thomas Gleixner 0eda58b7f3 genirq: Provide compat handling for chip->unmask()
Wrap the old chip function unmask() until the migration is complete
and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.043608928@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:37 +02:00
Thomas Gleixner e2c0f8ff0f genirq: Provide compat handling for chip->mask()
Wrap the old chip function mask() until the migration is complete and
the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.940355859@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:36 +02:00
Thomas Gleixner 3876ec9ef3 genirq: Provide compat handling for bus_lock/bus_sync_unlock
Wrap the old chip functions for bus_lock/bus_sync_unlock until the
migration is complete and the old chip functions are removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.842536121@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:35 +02:00
Thomas Gleixner a77c463591 genirq: Add new functions to dummy chips
The compat functions go away when the core code is converted.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:43:34 +02:00
Thomas Gleixner 6b8ff3120c genirq: Convert core code to irq_data
Convert all references in the core code to orq, chip, handler_data,
chip_data, msi_desc, affinity to irq_data.*

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:36:26 +02:00
Thomas Gleixner ff7dcd44dd genirq: Create irq_data
Low level chip functions need access to irq_desc->handler_data,
irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq
number to the low level functions, so they need to lookup irq_desc.
With sparse irq this means a radix tree lookup.

We could hand down irq_desc itself, but low level chip functions have
no need to fiddle with it directly and we want to restrict access to
irq_desc further.

Preparatory patch for new chip functions.

Note, that the ugly anon union/struct is there to avoid a full tree
wide clean up for now. This is not going to last 3 years like __do_IRQ()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.645542300@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 12:27:16 +02:00
Thomas Gleixner d9817ebeee genirq: Provide Kconfig
The generic irq Kconfig options are copied around all archs. Provide a
generic Kconfig file which can be included.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121843.217333624@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04 11:01:05 +02:00
Ira W. Snyder 399f1e30ac kfifo: fix scatterlist usage
The kfifo_dma family of functions use sg_mark_end() on the last element in
their scatterlist.  This forces use of a fresh scatterlist for each DMA
operation, which makes recycling a single scatterlist impossible.

Change the behavior of the kfifo_dma functions to match the usage of the
dma_map_sg function.  This means that users must respect the returned
nents value.  The sample code is updated to reflect the change.

This bug is trivial to cause: call kfifo_dma_in_prepare() such that it
prepares a scatterlist with a single entry comprising the whole fifo.
This is the case when you map the entirety of a newly created empty fifo.
This causes the setup_sgl() function to mark the first scatterlist entry
as the end of the chain, no matter what comes after it.

Afterwards, add and remove some data from the fifo such that another call
to kfifo_dma_in_prepare() will create two scatterlist entries.  It returns
nents=2.  However, due to the previous sg_mark_end() call, sg_is_last()
will now return true for the first scatterlist element.  This causes the
sample code to print a single scatterlist element when it should print
two.

By removing the call to sg_mark_end(), we make the API as similar as
possible to the DMA mapping API.  All users are required to respect the
returned nents.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-01 10:50:58 -07:00
Ingo Molnar a5a2bad55d Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-09-24 09:12:05 +02:00
Thomas Gleixner d1ea13c6e2 genirq: Cleanup irq_chip->typename leftovers
3 years transition phase is enough. Cleanup the last users and remove
the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Leo Chen <leochen@broadcom.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
2010-09-23 19:12:26 +02:00
Paul E. McKenney 269dcc1c2e rcu: Add tracing data to support queueing models
The current tracing data is not sufficient to deduce the average time
that a callback spends waiting for a grace period to end.  Add three
per-CPU counters recording the number of callbacks invoked (ci), the
number of callbacks orphaned (co), and the number of callbacks adopted
(ca).  Given the existing callback queue length (ql), the average wait
time in absence of CPU hotplug operations is ql/ci.  The units of wait
time will be in terms of the duration over which ci was measured.

In the presence of CPU hotplug operations, there is room for argument,
but ql/(ci-co+ca) won't steer you too far wrong.

Also fixes a typo called out by Lucas De Marchi <lucas.de.marchi@gmail.com>.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-09-23 09:16:53 -07:00
Paul E. McKenney 0ddea0ead2 rcu: fix sparse errors in rcutorture.c
Add the sparse __rcu address-space identifier and make a couple of
variables static.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-09-23 09:16:42 -07:00
Christian Dietrich 829f8ed2c9 kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC
The CONFIG_DEBUG_LOCK_ALLOC ifdef isn't necessary at this point, because it is
checked in an outer ifdef level already and has no effect here.

Signed-off-by: Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-09-23 09:14:51 -07:00
Joe Perches 99a51792db kernel/pm_qos_params.c: Remove unnecessary casts of private_data
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-09-23 13:33:46 +02:00
Stephen Rothwell 1ef21199a5 powerpc: define a compat_sys_recv cond_syscall
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-23 17:03:55 +10:00
Andrea Arcangeli a247c3a97a rmap: fix walk during fork
The below bug in fork led to the rmap walk finding the parent huge-pmd
twice instead of just once, because the anon_vma_chain objects of the
child vma still point to the vma->vm_mm of the parent.

The patch fixes it by making the rmap walk accurate during fork.  It's not
a big deal normally but it worth being accurate considering the cost is
the same.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-22 17:22:39 -07:00
Jason Baron 8f7b50c514 jump label: Tracepoint support for jump labels
Make use of the jump label infrastructure for tracepoints.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:31:01 -04:00
Jason Baron 4c3ef6d793 jump label: Add jump_label_text_reserved() to reserve jump points
Add a jump_label_text_reserved(void *start, void *end), so that other
pieces of code that want to modify kernel text, can first verify that
jump label has not reserved the instruction.

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <06236663a3a7b1c1f13576bb9eccb6d9c17b7bfe.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:30:46 -04:00
Jason Baron e0cf0cd496 jump label: Initialize workqueue tracepoints *before* they are registered
Initialize the workqueue data structures *before* they are registered
so that they are ready for callbacks.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <e3a3383fc370ac7086625bebe89d9480d7caf372.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:30:03 -04:00
Jason Baron bf5438fca2 jump label: Base patch for jump label
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>

[ cleaned up some formating ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:29:41 -04:00
Ingo Molnar 90edf27fb8 Merge branch 'linus' into perf/core
Conflicts:
	kernel/hw_breakpoint.c

Merge reason: resolve the conflict.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 18:45:01 +02:00