Commit Graph

128 Commits

Author SHA1 Message Date
Thomas Gleixner 06d8308c61 NOHZ: reevaluate idle sleep length after add_timer_on()
add_timer_on() can add a timer on a CPU which is currently in a long
idle sleep, but the timer wheel is not reevaluated by the nohz code on
that CPU. So a timer can be delayed for quite a long time. This
triggered a false positive in the clocksource watchdog code.

To avoid this we need to wake up the idle CPU and enforce the
reevaluation of the timer wheel for the next timer event.

Add a function, which checks a given CPU for idle state, marks the
idle task with NEED_RESCHED and sends a reschedule IPI to notify the
other CPU of the change in the timer wheel.

Call this function from add_timer_on().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org

--
 include/linux/sched.h |    6 ++++++
 kernel/sched.c        |   43 +++++++++++++++++++++++++++++++++++++++++++
 kernel/timer.c        |   10 +++++++++-
 3 files changed, 58 insertions(+), 1 deletion(-)
2008-03-26 08:28:55 +01:00
Harvey Harrison 7ad5b3a505 kernel: remove fastcall in kernel/*
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:31 -08:00
Pavel Emelyanov 6c5f3e7b43 Pidns: make full use of xxx_vnr() calls
Some time ago the xxx_vnr() calls (e.g.  pid_vnr or find_task_by_vpid) were
_all_ converted to operate on the current pid namespace.  After this each call
like xxx_nr_ns(foo, current->nsproxy->pid_ns) is nothing but a xxx_vnr(foo)
one.

Switch all the xxx_nr_ns() callers to use the xxx_vnr() calls where
appropriate.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:29 -08:00
Michael Neuling 06b8e878a9 taskstats scaled time cleanup
This moves the ability to scale cputime into generic code.  This allows us
to fix the issue in kernel/timer.c (noticed by Balbir) where we could only
add an unscaled value to the scaled utime/stime.

This adds a cputime_to_scaled function.  As before, the POWERPC version
does the scaling based on the last SPURR/PURR ratio calculated.  The
generic and s390 (only other arch to implement asm/cputime.h) versions are
both NOPs.

Also moves the SPURR and PURR snapshots closer.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:00 -08:00
Linus Torvalds 75659ca0c1 Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
  Remove commented-out code copied from NFS
  NFS: Switch from intr mount option to TASK_KILLABLE
  Add wait_for_completion_killable
  Add wait_event_killable
  Add schedule_timeout_killable
  Use mutex_lock_killable in vfs_readdir
  Add mutex_lock_killable
  Use lock_page_killable
  Add lock_page_killable
  Add fatal_signal_pending
  Add TASK_WAKEKILL
  exit: Use task_is_*
  signal: Use task_is_*
  sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
  ptrace: Use task_is_*
  power: Use task_is_*
  wait: Use TASK_NORMAL
  proc/base.c: Use task_is_*
  proc/array.c: Use TASK_REPORT
  perfmon: Use task_is_*
  ...

Fixed up conflicts in NFS/sunrpc manually..
2008-02-01 11:45:47 +11:00
Pavel Machek 4c9dc64122 time: timer cleanups
Small cleanups to tick-related code. Wrong preempt count is followed
by BUG(), so it is hardly KERN_WARNING.

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

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:00 +01:00
Peter Zijlstra d3d74453c3 hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback
Currently all highres=off timers are run from softirq context, but
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ timers expect to run from irq context.

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

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Randy Dunlap 48ccf3dac3 timer: fix section mismatch
The caller is __cpuinit.
Also, this code block and its caller are inside #ifdef CONFIG_HOTPLUG_CPU
blocks, so this code should reflect that config symbol's usage.

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

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@akpm@linux-foundation.org>
2008-01-21 19:39:41 -08:00
Roland McGrath 84427eaef1 remove task_ppid_nr_ns
task_ppid_nr_ns is called in three places.  One of these should never
have called it.  In the other two, using it broke the existing
semantics.  This was presumably accidental.  If the function had not
been there, it would have been much more obvious to the eye that those
patches were changing the behavior.  We don't need this function.

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

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

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

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-13 09:56:43 -08:00
Adrian Bunk b4be625852 timer: kernel/timer.c section fixes
This patch fixes the following section mismatches with CONFIG_HOTPLUG=n,
CONFIG_HOTPLUG_CPU=y:

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

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-18 18:05:58 +01:00
Matthew Wilcox 294d5cc233 Add schedule_timeout_killable
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:40:07 -05:00
Paul Mackerras fa13a5a1f2 sched: restore deterministic CPU accounting on powerpc
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().

This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before.  If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.

This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().

account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 22:39:38 +01:00
Li Zefan 8dce39c231 time: fix inconsistent function names in comments
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-05 15:12:33 -08:00
Pavel Emelyanov b488893a39 pid namespaces: changes to show virtual ids to user
This is the largest patch in the set. Make all (I hope) the places where
the pid is shown to or get from user operate on the virtual pids.

The idea is:
 - all in-kernel data structures must store either struct pid itself
   or the pid's global nr, obtained with pid_nr() call;
 - when seeking the task from kernel code with the stored id one
   should use find_task_by_pid() call that works with global pids;
 - when showing pid's numerical value to the user the virtual one
   should be used, but however when one shows task's pid outside this
   task's namespace the global one is to be used;
 - when getting the pid from userspace one need to consider this as
   the virtual one and use appropriate task/pid-searching functions.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: yet nuther build fix]
[akpm@linux-foundation.org: remove unneeded casts]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:40 -07:00
Michael Neuling c66f08be7e Add scaled time to taskstats based process accounting
This adds items to the taststats struct to account for user and system
time based on scaling the CPU frequency and instruction issue rates.

Adds account_(user|system)_time_scaled callbacks which architectures
can use to account for time using this mechanism.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:28 -07:00
Daniel Walker 5b4db0c2f2 whitespace fixes: system timers
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:26 -07:00
Tony Luck c36c282b88 Pull ia64-clocksource into release branch 2007-07-20 11:26:47 -07:00
Bob Picco 1f564ad6d4 [IA64] remove time interpolator
Remove time_interpolator code (This is generic code, but
only user was ia64.  It has been superseded by the
CONFIG_GENERIC_TIME code).

Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Peter Keilty <peter.keilty@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-07-20 11:23:02 -07:00
Thomas Gleixner 6819457d2c timer.c: cleanup recently introduced whitespace damage
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:52 -07:00
Christoph Lameter 94f6030ca7 Slab allocators: Replace explicit zeroing with __GFP_ZERO
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past.  But with __GFP_ZERO it is possible now to do zeroing
while allocating.

Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Venki Pallipadi c5c061b8f9 Add a flag to indicate deferrable timers in /proc/timer_stats
Add a flag in /proc/timer_stats to indicate deferrable timers.  This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.

Deferrable timer and normal timer will appear in /proc/timer_stats as below.
  10D,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   10,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)

Also version of timer_stats changes from v0.1 to v0.2

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:45 -07:00
Tomas Janousek d62141414a Use boot based time for uptime in /proc
Commit 411187fb05 caused uptime not to increase
during suspend.  This may cause confusion so I restore the old behaviour by
using the boot based time instead of monotonic for uptime.

Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:41 -07:00
Thomas Gleixner eaad084bb0 NOHZ: prevent multiplication overflow - stop timer for huge timeouts
get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case
there is no timer pending. On 64 bit machines this results in a
multiplication overflow in tick_nohz_stop_sched_tick().

Reported by: Dave Miller <davem@davemloft.net>

Make the return value a constant and limit the return value to a 32 bit
value.

When the max timeout value is returned, we can safely stop the tick
timer device. The max jiffies delta results in a 12 days timeout for
HZ=1000.

In the long term the get_next_timer_interrupt() code needs to be
reworked to return ktime instead of jiffies, but we have to wait until
the last users of the original NO_IDLE_HZ code are converted.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-29 18:11:10 -07:00
Thomas Gleixner d10ff3fb62 timekeeping fix patch got mis-applied
The time keeping code move to kernel/time/timekeeping.c broke the
clocksource resume logic patch, which got applied to the old file by a
fuzzy application.  Fix it up and move the clocksource_resume() call to
the appropriate place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ tssk, tssk, everybody should use --fuzz=0 ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-14 12:13:11 -07:00
akpm@linux-foundation.org e9910846fd timer: revert parenthesis fix in tbase_get_deferrable() etc
On 09-05-2007 21:10, Pallipadi, Venkatesh wrote:
...
> On a 64 bit system, converting pointer to int causes unnecessary
> compiler warning, and intermediate long conversion was to avoid that.
> I will have to rephrase my comment to remove 32 bit value and use int,
> as that is what the function returns.

So, this patch reverts all changes done by my previous patch.

I apologize for my wrong comment about "logical error" here.

Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Satyam Sharma <satyam.sharma@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 09:26:53 -07:00
Thomas Gleixner b52f52a093 clocksource: fix resume logic
We need to make sure that the clocksources are resumed, when timekeeping is
resumed.  The current resume logic does not guarantee this.

Add a resume function pointer to the clocksource struct, so clocksource
drivers which need to reinitialize the clocksource can provide a resume
function.

Add a resume function, which calls the maybe available clocksource resume
functions and resets the watchdog function, so a stable TSC can be used
accross suspend/resume.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Rafael J. Wysocki 8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Jarek Poplawski 38a23e311b timer: parenthesis fix in tbase_get_deferrable() etc
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:55 -07:00
Pavel Emelianov b5e618181a Introduce a handy list_first_entry macro
There are many places in the kernel where the construction like

   foo = list_entry(head->next, struct foo_struct, list);

are used.
The code might look more descriptive and neat if using the macro

   list_first_entry(head, type, member) \
             list_entry((head)->next, type, member)

Here is the macro itself and the examples of its usage in the generic code.
 If it will turn out to be useful, I can prepare the set of patches to
inject in into arch-specific code, drivers, networking, etc.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:11 -07:00
john stultz 8524070b79 Move timekeeping code to timekeeping.c
Move the timekeeping code out of kernel/timer.c and into
kernel/time/timekeeping.c.  I made no cleanups or other changes in transit.

[akpm@linux-foundation.org: build fix]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:06 -07:00
Venki Pallipadi 6e453a6751 Add support for deferrable timers
Introduce a new flag for timers - deferrable: Timers that work normally
when system is busy.  But, will not cause CPU to come out of idle (just to
service this timer), when CPU is idle.  Instead, this timer will be
serviced when CPU eventually wakes up with a subsequent non-deferrable
timer.

The main advantage of this is to avoid unnecessary timer interrupts when
CPU is idle.  If the routine currently called by a timer can wait until
next event without any issues, this new timer can be used to setup timer
event for that routine.  This, with dynticks, allows CPUs to be lazy,
allowing them to stay in idle for extended period of time by reducing
unnecesary wakeup and thereby reducing the power consumption.

This patch:

Builds this new timer on top of existing timer infrastructure.  It uses
last bit in 'base' pointer of timer_list structure to store this deferrable
timer flag.  __next_timer_interrupt() function skips over these deferrable
timers when CPU looks for next timer event for which it has to wake up.

This is exported by a new interface init_timer_deferrable() that can be
called in place of regular init_timer().

[akpm@linux-foundation.org: Privatise a #define]
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:05 -07:00
David Howells e19dff1fdd [AF_RXRPC]: Make it possible to merely try to cancel timers from a module
Export try_to_del_timer_sync() for use by the AF_RXRPC module.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 15:46:56 -07:00
Ingo Molnar 995f054f2a [PATCH] high-res timers: resume fix
Soeren Sonnenburg reported that upon resume he is getting
this backtrace:

 [<c0119637>] smp_apic_timer_interrupt+0x57/0x90
 [<c0142d30>] retrigger_next_event+0x0/0xb0
 [<c0104d30>] apic_timer_interrupt+0x28/0x30
 [<c0142d30>] retrigger_next_event+0x0/0xb0
 [<c0140068>] __kfifo_put+0x8/0x90
 [<c0130fe5>] on_each_cpu+0x35/0x60
 [<c0143538>] clock_was_set+0x18/0x20
 [<c0135cdc>] timekeeping_resume+0x7c/0xa0
 [<c02aabe1>] __sysdev_resume+0x11/0x80
 [<c02ab0c7>] sysdev_resume+0x47/0x80
 [<c02b0b05>] device_power_up+0x5/0x10

it turns out that on resume we mistakenly re-enable interrupts too
early.  Do the timer retrigger only on the current CPU.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Soeren Sonnenburg <kernel@nn7.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-07 10:03:43 -07:00
Thomas Gleixner 9501b6cf55 [PATCH] dynticks: fix hrtimer rounding error in next_timer_interrupt
The rework of next_timer_interrupt() fixed the timer wheel bugs, but
invented a rounding error versus the next hrtimer event. This is caused
by the conversion of the hrtimer internal representation to relative
jiffies.

This causes bug #8100:
http://bugzilla.kernel.org/show_bug.cgi?id=8100

next_timer_interrupt() returns "now" in such a case and causes the code
in tick_nohz_stop_sched_tick() to trigger the timer softirq, which is
bogus as no timer is due for expiry. This results in an endless context
switching between idle and ksoftirqd until a timer is due for expiry.

Modify the hrtimer evaluation so that, it returns now + 1, when the
conversion results in a delta < 1 jiffie.

It's confirmed to resolve bug #8100

Reported-by: Emil Karlson <jkarlson@cc.hut.fi>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-25 14:57:34 -07:00
Daniel Walker 90675a27fa [PATCH] fix vsyscall settimeofday
I've only seen this on x86_64.

The vsyscall state only gets updated when a timer interrupts comes in.  So
if the time is set long before the next timer, there will be a period when
a gettimeofday() won't reflect the correct time.

I added an explicit update_vsyscall() during the settimeofday(), that way
the vsyscall state doesn't get stale.

Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 09:30:25 -08:00
Thomas Gleixner 6321dd60c7 [PATCH] Save/restore periodic tick information over suspend/resume
The programming of periodic tick devices needs to be saved/restored
across suspend/resume - otherwise we might end up with a system coming
up that relies on getting a PIT (or HPET) interrupt, while those devices
default to 'no interrupts' after powerup. (To confuse things it worked
to a certain degree on some systems because the lapic gets initialized
as a side-effect of SMP bootup.)

This suspend / resume thing was dropped unintentionally during the
last-minute -mm code reshuffling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 09:30:24 -08:00
Heiko Carstens e81ce1f7ec [PATCH] timer/hrtimer: take per cpu locks in sane order
Doing something like this on a two cpu system

  # echo 0 > /sys/devices/system/cpu/cpu0/online
  # echo 1 > /sys/devices/system/cpu/cpu0/online
  # echo 0 > /sys/devices/system/cpu/cpu1/online

will give me this:

  =======================================================
  [ INFO: possible circular locking dependency detected ]
  2.6.21-rc2-g562aa1d4-dirty #7
  -------------------------------------------------------
  bash/1282 is trying to acquire lock:
   (&cpu_base->lock_key){.+..}, at: [<000000000005f17e>] hrtimer_cpu_notify+0xc6/0x240

  but task is already holding lock:
   (&cpu_base->lock_key#2){.+..}, at: [<000000000005f174>] hrtimer_cpu_notify+0xbc/0x240

  which lock already depends on the new lock.

This happens because we have the following code in kernel/hrtimer.c:

  migrate_hrtimers(int cpu)
  [...]
  old_base = &per_cpu(hrtimer_bases, cpu);
  new_base = &get_cpu_var(hrtimer_bases);
  [...]
  spin_lock(&new_base->lock);
  spin_lock(&old_base->lock);

Which means the spinlocks are taken in an order which depends on which cpu
gets shut down from which other cpu. Therefore lockdep complains that there
might be an ABBA deadlock. Since migrate_hrtimers() gets only called on
cpu hotplug it's safe to assume that it isn't executed concurrently on a

The same problem exists in kernel/timer.c: migrate_timers().

As pointed out by Christian Borntraeger one possible solution to avoid
the locking order complaints would be to make sure that the locks are
always taken in the same order. E.g. by taking the lock of the cpu with
the lower number first.

To achieve this we introduce two new spinlock functions double_spin_lock
and double_spin_unlock which lock or unlock two locks in a given order.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Christian Borntraeger <cborntra@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 07:57:53 -08:00
Randy Dunlap 05fb6bf0b2 [PATCH] kernel-doc fixes for 2.6.20-git15 (non-drivers)
Fix kernel-doc warnings in 2.6.20-git15 (lib/, mm/, kernel/, include/).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:37 -08:00
Daniel Walker 9d63463114 [PATCH] update timekeeping_is_continuous comment
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:36 -08:00
john stultz acc9a9dcdd [PATCH] generic: vsyscall-gtod support for GENERIC_TIME
Provides generic infrastructure for vsyscall-gtod.

[akpm@osdl.org: cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Roman Zippel <zippel@linux-m68k.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:14:00 -08:00
Ingo Molnar 82f67cd9fc [PATCH] Add debugging feature /proc/timer_stat
Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.

Sample output:

# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
  24,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
  11,     0 swapper          sk_reset_timer (tcp_delack_timer)
   6,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
  17,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   4,  2050 pcscd            do_nanosleep (hrtimer_wakeup)
   5,  4179 sshd             sk_reset_timer (tcp_write_timer)
   4,  2248 yum-updatesd     schedule_timeout (process_timeout)
  18,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   3,     0 swapper          sk_reset_timer (tcp_delack_timer)
   1,     1 swapper          neigh_table_init_no_netlink (neigh_periodic_timer)
   2,     1 swapper          e1000_up (e1000_watchdog)
   1,     1 init             schedule_timeout (process_timeout)
100 total events, 25.24 events/sec

[ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:59 -08:00
Thomas Gleixner 79bf2bb335 [PATCH] tick-management: dyntick / highres functionality
With Ingo Molnar <mingo@elte.hu>

Add functions to provide dynamic ticks and high resolution timers.  The code
which keeps track of jiffies and handles the long idle periods is shared
between tick based and high resolution timer based dynticks.  The dyntick
functionality can be disabled on the kernel commandline.  Provide also the
infrastructure to support high resolution timers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:59 -08:00
Thomas Gleixner d316c57ff6 [PATCH] clockevents: add core functionality
Architectures register their clock event devices, in the clock events core.
Users of the clockevents core can get clock event devices for their use.  The
clockevents core code provides notification mechanisms for various clock
related management events.

This allows to control the clock event devices without the architectures
having to worry about the details of function assignment.  This is also a
preliminary for high resolution timers and dynamic ticks to allow the core
code to control the clock functionality without intrusive changes to the
architecture code.

[Fixes-by: Ingo Molnar <mingo@elte.hu>]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:59 -08:00
Thomas Gleixner fd064b9b77 [PATCH] Extend next_timer_interrupt() to use a reference jiffie
For CONFIG_NO_HZ we need to calculate the next timer wheel event based on a
given jiffie value.  Extend the existing code to allow the extra 'now'
argument.  Provide a compability function for the existing implementations to
call the function with now == jiffies.  (This also solves the racyness of the
original code vs.  jiffies changing during the iteration.)

No functional changes to existing users of this infrastructure.

[ remove WARN_ON() that triggered on s390, by Carsten Otte <cotte@de.ibm.com> ]
[ made new helper static, Adrian Bunk <bunk@stusta.de> ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:58 -08:00
Thomas Gleixner 1cfd68496e [PATCH] Fix cascade lookup of next_timer_interrupt
When searching for the next pending timer in the timer wheel we need to take
the cascade into account.  The current code has several problems:

 1. it looks into the previous cascade
 2. it ignores a pending cascade
 3. it ignores multiple cascades

Change the cascade lookup, so it calculates the array index from the point of
the next cascade and always look at the cascade buckets, when the cascade is
pending, i.e.  gets executed in the next timer softirq.  When multiple
cascades are pending, then lookup the next buckets too.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:58 -08:00
Thomas Gleixner 5d8b34fdcb [PATCH] clocksource: Add verification (watchdog) helper
The TSC needs to be verified against another clocksource.  Instead of using
hardwired assumptions of available hardware, provide a generic verification
mechanism.  The verification uses the best available clocksource and handles
the usability for high resolution timers / dynticks of the clocksource which
needs to be verified.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:57 -08:00
Thomas Gleixner 7e69f2b1ea [PATCH] clocksource: Remove the update callback
The clocksource code allows direct updates of the rating of a given
clocksource now.  Change TSC unstable tracking to use this interface and
remove the update callback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:57 -08:00
Thomas Gleixner 73b08d2aa4 [PATCH] clocksource: replace is_continuous by a flag field
Using a flag filed allows to encode more than one information into a variable.
Preparatory patch for the generic clocksource verification.

[mingo@elte.hu: convert vmitime.c to the new clocksource flag]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:57 -08:00
John Stultz 411187fb05 [PATCH] GTOD: persistent clock support
Persistent clock support: do proper timekeeping across suspend/resume.

[bunk@stusta.de: cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:57 -08:00