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  1. 25 11月, 2008 19 次提交
  3. 23 11月, 2008 2 次提交
  5. 21 11月, 2008 1 次提交
    • V
      sched: update comment for move_task_off_dead_cpu · 957ad016
      由 Vegard Nossum 提交于 
      Impact: cleanup

This commit:

commit f7b4cddc
Author: Oleg Nesterov <oleg@tv-sign.ru>
Date:   Tue Oct 16 23:30:56 2007 -0700

    do CPU_DEAD migrating under read_lock(tasklist) instead of write_lock_irq(ta

    Currently move_task_off_dead_cpu() is called under
    write_lock_irq(tasklist).  This means it can't use task_lock() which is
    needed to improve migrating to take task's ->cpuset into account.

    Change the code to call move_task_off_dead_cpu() with irqs enabled, and
    change migrate_live_tasks() to use read_lock(tasklist).

...forgot to update the comment in front of move_task_off_dead_cpu.

Reference: http://lkml.org/lkml/2008/6/23/135Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      957ad016
  7. 20 11月, 2008 1 次提交
    • K
      sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares · ec4e0e2f
      由 Ken Chen 提交于 
      Impact: make load-balancing more consistent

In the update_shares() path leading to tg_shares_up(), the calculation of
per-cpu cfs_rq shares is rather erratic even under moderate task wake up
rate.  The problem is that the per-cpu tg->cfs_rq load weight used in the
sd_rq_weight aggregation and actual redistribution of the cfs_rq->shares
are collected at different time.  Under moderate system load, we've seen
quite a bit of variation on the cfs_rq->shares and ultimately wildly
affects sched_entity's load weight.

This patch caches the result of initial per-cpu load weight when doing the
sum calculation, and then pass it down to update_group_shares_cpu() for
redistributing per-cpu cfs_rq shares.  This allows consistent total cfs_rq
shares across all CPUs. It also simplifies the rounding and zero load
weight check.
Signed-off-by: NKen Chen <kenchen@google.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      ec4e0e2f
  9. 18 11月, 2008 1 次提交
    • L
      cpuset: fix regression when failed to generate sched domains · 700018e0
      由 Li Zefan 提交于 
      Impact: properly rebuild sched-domains on kmalloc() failure

When cpuset failed to generate sched domains due to kmalloc()
failure, the scheduler should fallback to the single partition
'fallback_doms' and rebuild sched domains, but now it only
destroys but not rebuilds sched domains.

The regression was introduced by:

| commit dfb512ec
| Author: Max Krasnyansky <maxk@qualcomm.com>
| Date:   Fri Aug 29 13:11:41 2008 -0700
|
|    sched: arch_reinit_sched_domains() must destroy domains to force rebuild

After the above commit, partition_sched_domains(0, NULL, NULL) will
only destroy sched domains and partition_sched_domains(1, NULL, NULL)
will create the default sched domain.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      700018e0
  11. 17 11月, 2008 1 次提交
  13. 16 11月, 2008 1 次提交
    • M
      tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() · 7e066fb8
      由 Mathieu Desnoyers 提交于 
      Impact: API *CHANGE*. Must update all tracepoint users.

Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint
structure in a single spot for all the kernel. It helps reducing memory
consumption, especially when declaring a lot of tracepoints, e.g. for
kmalloc tracing.

*API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for
tracepoint declarations rather than DEFINE_TRACE(). This is the sane way
to do it. The name previously used was misleading.

Updates scheduler instrumentation to follow this API change.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7e066fb8
  15. 13 11月, 2008 1 次提交
    • I
      sched: fix init_idle()'s use of sched_clock() · 5cbd54ef
      由 Ingo Molnar 提交于 
      Maciej Rutecki reported:

> I have this bug during suspend to disk:
>
> [  188.592151] Enabling non-boot CPUs ...
> [  188.592151] SMP alternatives: switching to SMP code
> [  188.666058] BUG: using smp_processor_id() in preemptible
> [00000000]
> code: suspend_to_disk/2934
> [  188.666064] caller is native_sched_clock+0x2b/0x80

Which, as noted by Linus, was caused by me, via:

  7cbaef9c "sched: optimize sched_clock() a bit"

Move the rq locking a bit earlier in the initialization sequence,
that will make the sched_clock() call in init_idle() non-preemptible.
Reported-by: NMaciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      5cbd54ef
  17. 12 11月, 2008 1 次提交
  19. 11 11月, 2008 2 次提交
  21. 10 11月, 2008 1 次提交
  23. 07 11月, 2008 4 次提交
  25. 05 11月, 2008 1 次提交
    • P
      sched: backward looking buddy · 4793241b
      由 Peter Zijlstra 提交于 
      Impact: improve/change/fix wakeup-buddy scheduling

Currently we only have a forward looking buddy, that is, we prefer to
schedule to the task we last woke up, under the presumption that its
going to consume the data we just produced, and therefore will have
cache hot benefits.

This allows co-waking producer/consumer task pairs to run ahead of the
pack for a little while, keeping their cache warm. Without this, we
would interleave all pairs, utterly trashing the cache.

This patch introduces a backward looking buddy, that is, suppose that
in the above scenario, the consumer preempts the producer before it
can go to sleep, we will therefore miss the wakeup from consumer to
producer (its already running, after all), breaking the cycle and
reverting to the cache-trashing interleaved schedule pattern.

The backward buddy will try to schedule back to the task that woke us
up in case the forward buddy is not available, under the assumption
that the last task will be the one with the most cache hot task around
barring current.

This will basically allow a task to continue after it got preempted.

In order to avoid starvation, we allow either buddy to get wakeup_gran
ahead of the pack.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4793241b
  27. 04 11月, 2008 3 次提交
  29. 30 10月, 2008 1 次提交