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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-07-09 15:12:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-07-17 12:05:44 +0200 |
| commit | 396e894d289d69bacf5acd983c97cd6e21a14c08 (patch) | |
| tree | ec3e3ba19e332a799e1229f62663625d9c7583dd | |
| parent | f469461df6ff822f71b8737bda86eea20f16ff93 (diff) | |
| download | kernel_samsung_tuna-396e894d289d69bacf5acd983c97cd6e21a14c08.zip kernel_samsung_tuna-396e894d289d69bacf5acd983c97cd6e21a14c08.tar.gz kernel_samsung_tuna-396e894d289d69bacf5acd983c97cd6e21a14c08.tar.bz2 | |
sched: Revert nohz_ratelimit() for now
Norbert reported that nohz_ratelimit() causes his laptop to burn about
4W (40%) extra. For now back out the change and see if we can adjust
the power management code to make better decisions.
Reported-by: Norbert Preining <preining@logic.at>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/sched.h | 6 | ||||
| -rw-r--r-- | kernel/sched.c | 10 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 2 |
3 files changed, 1 insertions, 17 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 747fcae..6e0bb86 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -273,17 +273,11 @@ extern cpumask_var_t nohz_cpu_mask; #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) extern int select_nohz_load_balancer(int cpu); extern int get_nohz_load_balancer(void); -extern int nohz_ratelimit(int cpu); #else static inline int select_nohz_load_balancer(int cpu) { return 0; } - -static inline int nohz_ratelimit(int cpu) -{ - return 0; -} #endif /* diff --git a/kernel/sched.c b/kernel/sched.c index f52a880..63b4a14 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1232,16 +1232,6 @@ void wake_up_idle_cpu(int cpu) smp_send_reschedule(cpu); } -int nohz_ratelimit(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - u64 diff = rq->clock - rq->nohz_stamp; - - rq->nohz_stamp = rq->clock; - - return diff < (NSEC_PER_SEC / HZ) >> 1; -} - #endif /* CONFIG_NO_HZ */ static u64 sched_avg_period(void) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 813993b..f898af6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -325,7 +325,7 @@ void tick_nohz_stop_sched_tick(int inidle) } while (read_seqretry(&xtime_lock, seq)); if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) || - arch_needs_cpu(cpu) || nohz_ratelimit(cpu)) { + arch_needs_cpu(cpu)) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; } else { |