Skip to content

C
clone-Linux

gsplhtlxg / clone-Linux

通知 2
Star 0
Fork 1
C
clone-Linux

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 29 12月, 2008 9 次提交
    • G
      sched: add sched_class->needs_post_schedule() member · 967fc046
      由 Gregory Haskins 提交于 
      We currently run class->post_schedule() outside of the rq->lock, which
means that we need to test for the need to post_schedule outside of
the lock to avoid a forced reacquistion.  This is currently not a problem
as we only look at rq->rt.overloaded.  However, we want to enhance this
going forward to look at more state to reduce the need to post_schedule to
a bare minimum set.  Therefore, we introduce a new member-func called
needs_post_schedule() which tests for the post_schedule condtion without
actually performing the work.  Therefore it is safe to call this
function before the rq->lock is released, because we are guaranteed not
to drop the lock at an intermediate point (such as what post_schedule()
may do).

We will use this later in the series

[ rostedt: removed paranoid BUG_ON ]
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      967fc046
    • G
      sched: make double-lock-balance fair · 8f45e2b5
      由 Gregory Haskins 提交于 
      double_lock balance() currently favors logically lower cpus since they
often do not have to release their own lock to acquire a second lock.
The result is that logically higher cpus can get starved when there is
a lot of pressure on the RQs.  This can result in higher latencies on
higher cpu-ids.

This patch makes the algorithm more fair by forcing all paths to have
to release both locks before acquiring them again.  Since callsites to
double_lock_balance already consider it a potential preemption/reschedule
point, they have the proper logic to recheck for atomicity violations.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      8f45e2b5
    • G
      sched: pull only one task during NEWIDLE balancing to limit critical section · 7e96fa58
      由 Gregory Haskins 提交于 
      git-id c4acb2c0 attempted to limit
newidle critical section length by stopping after at least one task
was moved.  Further investigation has shown that there are other
paths nested further inside the algorithm which still remain that allow
long latencies to occur with newidle balancing.  This patch applies
the same technique inside balance_tasks() to limit the duration of
this optional balancing operation.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
CC: Nick Piggin <npiggin@suse.de>
      7e96fa58
    • G
      sched: only try to push a task on wakeup if it is migratable · 777c2f38
      由 Gregory Haskins 提交于 
      There is no sense in wasting time trying to push a task away that
cannot move anywhere else.  We gain no benefit from trying to push
other tasks at this point, so if the task being woken up is non
migratable, just skip the whole operation.  This reduces overhead
in the wakeup path for certain tasks.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      777c2f38
    • G
      sched: use highest_prio.next to optimize pull operations · 74ab8e4f
      由 Gregory Haskins 提交于 
      We currently take the rq->lock for every cpu in an overload state during
pull_rt_tasks().  However, we now have enough information via the
highest_prio.[curr|next] fields to determine if there is any tasks of
interest to warrant the overhead of the rq->lock, before we actually take
it.  So we use this information to reduce lock contention during the
pull for the case where the source-rq doesnt have tasks that preempt
the current task.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      74ab8e4f
    • G
      sched: use highest_prio.curr for pull threshold · a8728944
      由 Gregory Haskins 提交于 
      highest_prio.curr is actually a more accurate way to keep track of
the pull_rt_task() threshold since it is always up to date, even
if the "next" task migrates during double_lock.  Therefore, stop
looking at the "next" task object and simply use the highest_prio.curr.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      a8728944
    • G
      sched: track the next-highest priority on each runqueue · e864c499
      由 Gregory Haskins 提交于 
      We will use this later in the series to reduce the amount of rq-lock
contention during a pull operation
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      e864c499
    • G
      sched: cleanup inc/dec_rt_tasks · 4d984277
      由 Gregory Haskins 提交于 
      Move some common definitions up to the function prologe to simplify the
body logic.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
      4d984277
    • S
      x86: mark get_cpu_leaves() with __cpuinit annotation · 6092848a
      由 Sergio Luis 提交于 
      Impact: fix section mismatch warning

Commit b2bb8554 ("x86: Remove cpumask games
in x86/kernel/cpu/intel_cacheinfo.c") introduced get_cpu_leaves(), which
references __cpuinit cpuid4_cache_lookup().

Mark get_cpu_leaves() with a __cpuinit annotation.
Signed-off-by: NSergio Luis <sergio@larces.uece.br>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      6092848a
  3. 24 12月, 2008 4 次提交
  5. 19 12月, 2008 10 次提交
  7. 18 12月, 2008 17 次提交