[tip:sched/urgent] sched: Revert nohz_ratelimit() for now
in [Kernel]
|
Prev: could not catch the absolute path on intercept the mkdir() syscall in linux
Next: [tip:perf/core] perf probe: Fix the logic of die_compare_name
From: tip-bot for Peter Zijlstra on 17 Jul 2010 07:20 Commit-ID: 396e894d289d69bacf5acd983c97cd6e21a14c08 Gitweb: http://git.kernel.org/tip/396e894d289d69bacf5acd983c97cd6e21a14c08 Author: Peter Zijlstra <a.p.zijlstra(a)chello.nl> AuthorDate: Fri, 9 Jul 2010 15:12:27 +0200 Committer: Ingo Molnar <mingo(a)elte.hu> CommitDate: Sat, 17 Jul 2010 12:05:44 +0200 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(a)logic.at> Signed-off-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Acked-by: Mike Galbraith <efault(a)gmx.de> Cc: Arjan van de Ven <arjan(a)infradead.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo(a)elte.hu> --- include/linux/sched.h | 6 ------ kernel/sched.c | 10 ---------- 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 { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |