76 lines
2.2 KiB
Diff
76 lines
2.2 KiB
Diff
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
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Date: Fri, 9 Jul 2010 13:12:27 +0000 (+0200)
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Subject: sched: Revert nohz_ratelimit() for now
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fx86%2Flinux-2.6-tip.git;a=commitdiff_plain;h=396e894d289d69bacf5acd983c97cd6e21a14c08
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sched: Revert nohz_ratelimit() for now
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Norbert reported that nohz_ratelimit() causes his laptop to burn about
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4W (40%) extra. For now back out the change and see if we can adjust
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the power management code to make better decisions.
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Reported-by: Norbert Preining <preining@logic.at>
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Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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Acked-by: Mike Galbraith <efault@gmx.de>
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Cc: Arjan van de Ven <arjan@infradead.org>
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LKML-Reference: <new-submission>
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Signed-off-by: Ingo Molnar <mingo@elte.hu>
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---
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diff --git a/include/linux/sched.h b/include/linux/sched.h
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index 747fcae..6e0bb86 100644
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--- a/include/linux/sched.h
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+++ b/include/linux/sched.h
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@@ -273,17 +273,11 @@ extern cpumask_var_t nohz_cpu_mask;
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#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
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extern int select_nohz_load_balancer(int cpu);
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extern int get_nohz_load_balancer(void);
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-extern int nohz_ratelimit(int cpu);
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#else
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static inline int select_nohz_load_balancer(int cpu)
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{
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return 0;
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}
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-
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-static inline int nohz_ratelimit(int cpu)
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-{
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- return 0;
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-}
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#endif
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/*
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diff --git a/kernel/sched.c b/kernel/sched.c
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index f52a880..63b4a14 100644
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--- a/kernel/sched.c
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+++ b/kernel/sched.c
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@@ -1232,16 +1232,6 @@ void wake_up_idle_cpu(int cpu)
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smp_send_reschedule(cpu);
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}
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-int nohz_ratelimit(int cpu)
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-{
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- struct rq *rq = cpu_rq(cpu);
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- u64 diff = rq->clock - rq->nohz_stamp;
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-
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- rq->nohz_stamp = rq->clock;
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-
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- return diff < (NSEC_PER_SEC / HZ) >> 1;
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-}
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-
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#endif /* CONFIG_NO_HZ */
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static u64 sched_avg_period(void)
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diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
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index 813993b..f898af6 100644
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--- a/kernel/time/tick-sched.c
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+++ b/kernel/time/tick-sched.c
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@@ -325,7 +325,7 @@ void tick_nohz_stop_sched_tick(int inidle)
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} while (read_seqretry(&xtime_lock, seq));
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if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
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- arch_needs_cpu(cpu) || nohz_ratelimit(cpu)) {
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+ arch_needs_cpu(cpu)) {
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next_jiffies = last_jiffies + 1;
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delta_jiffies = 1;
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} else {
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