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  1. 16 Jul, 2007 1 commit
  3. 09 May, 2007 1 commit
    • Rafael J. Wysocki's avatar
      Add suspend-related notifications for CPU hotplug · 8bb78442
      Rafael J. Wysocki authored 
      
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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8bb78442
  5. 08 May, 2007 1 commit
  7. 27 Apr, 2007 1 commit
  9. 26 Apr, 2007 1 commit
    • Patrick McHardy's avatar
      [NET_SCHED]: Use ktime as clocksource · 641b9e0e
      Patrick McHardy authored 
      
Get rid of the manual clock source selection mess and use ktime. Also
use a scalar representation, which allows to clean up pkt_sched.h a bit
more and results in less ktime_to_ns() calls in most cases.

The PSCHED_US2JIFFIE/PSCHED_JIFFIE2US macros are implemented quite
inefficient by this patch, following patches will convert all qdiscs
to hrtimers and get rid of them entirely.
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      641b9e0e
  11. 07 Apr, 2007 1 commit
    • Ingo Molnar's avatar
      [PATCH] high-res timers: resume fix · 995f054f
      Ingo Molnar authored 
      
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: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarSoeren Sonnenburg <kernel@nn7.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      995f054f
  13. 28 Mar, 2007 1 commit
  15. 16 Mar, 2007 2 commits
  17. 06 Mar, 2007 1 commit
  19. 05 Mar, 2007 1 commit
    • Heiko Carstens's avatar
      [PATCH] timer/hrtimer: take per cpu locks in sane order · e81ce1f7
      Heiko Carstens authored 
      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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e81ce1f7
  21. 16 Feb, 2007 11 commits
  23. 11 Feb, 2007 1 commit
  25. 29 Sep, 2006 1 commit
  27. 14 Aug, 2006 1 commit
  29. 31 Jul, 2006 1 commit
  31. 03 Jul, 2006 2 commits
  33. 27 Jun, 2006 2 commits
  35. 25 Jun, 2006 2 commits
  37. 31 May, 2006 1 commit
  39. 26 Apr, 2006 2 commits
  41. 21 Apr, 2006 1 commit
  43. 11 Apr, 2006 1 commit
  45. 31 Mar, 2006 3 commits