From: Arjan van de Ven on 14 Jun 2010 10:40 On Mon, 14 Jun 2010 17:09:41 +0300 Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> wrote: > Hello, > Not sure if this simple solution is the correct one. it's not; the caller needs to pass in the cpu number I suspect for this to be really correct.... I just returned from family emergency travel and will take a look today -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/
From: Sergey Senozhatsky on 14 Jun 2010 11:00 On (06/14/10 07:38), Arjan van de Ven wrote: > > Hello, > > Not sure if this simple solution is the correct one. > > it's not; the caller needs to pass in the cpu number I suspect for this > to be really correct.... > > I just returned from family emergency travel and will take a look today > I thought about patching ./drivers/cpuidle/governors/menu.c: if (nr_iowait_cpu()) ./drivers/cpuidle/governors/menu.c: mult += 10 * nr_iowait_cpu(); ./kernel/time/tick-sched.c: if (nr_iowait_cpu() > 0) decided to patch nr_iowait_cpu instead. Sergey
From: Arjan van de Ven on 14 Jun 2010 11:00 On Mon, 14 Jun 2010 17:54:40 +0300 Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> wrote: > On (06/14/10 07:38), Arjan van de Ven wrote: > > > Hello, > > > Not sure if this simple solution is the correct one. > > > > it's not; the caller needs to pass in the cpu number I suspect for > > this to be really correct.... > > > > I just returned from family emergency travel and will take a look > > today > > > > I thought about patching > > ./drivers/cpuidle/governors/menu.c: if (nr_iowait_cpu()) > ./drivers/cpuidle/governors/menu.c: mult += 10 * > nr_iowait_cpu(); ./kernel/time/tick-sched.c: if > (nr_iowait_cpu() > 0) > > > decided to patch nr_iowait_cpu instead. the bug is that it needs to be nr_iowait_cpu(int cpu) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/
From: Sergey Senozhatsky on 14 Jun 2010 11:20 On (06/14/10 08:01), Arjan van de Ven wrote: > > decided to patch nr_iowait_cpu instead. > > the bug is that it needs to be > > nr_iowait_cpu(int cpu) > Something similar to this? --- diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 52ff8aa..4871ed5 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -137,14 +137,17 @@ static inline int which_bucket(unsigned int duration) { int bucket = 0; + int cpu = get_cpu(); /* * We keep two groups of stats; one with no * IO pending, one without. * This allows us to calculate * E(duration)|iowait */ - if (nr_iowait_cpu()) + if (nr_iowait_cpu(cpu)) bucket = BUCKETS/2; + + put_cpu(); if (duration < 10) return bucket; @@ -169,14 +172,17 @@ static inline int which_bucket(unsigned int duration) static inline int performance_multiplier(void) { int mult = 1; - + int cpu = get_cpu(); + /* for higher loadavg, we are more reluctant */ mult += 2 * get_loadavg(); /* for IO wait tasks (per cpu!) we add 5x each */ - mult += 10 * nr_iowait_cpu(); + mult += 10 * nr_iowait_cpu(cpu); + put_cpu(); + return mult; } diff --git a/include/linux/sched.h b/include/linux/sched.h index f118809..747fcae 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -139,7 +139,7 @@ extern int nr_processes(void); extern unsigned long nr_running(void); extern unsigned long nr_uninterruptible(void); extern unsigned long nr_iowait(void); -extern unsigned long nr_iowait_cpu(void); +extern unsigned long nr_iowait_cpu(int cpu); extern unsigned long this_cpu_load(void); diff --git a/kernel/sched.c b/kernel/sched.c index f8b8996..f61b48e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2864,9 +2864,9 @@ unsigned long nr_iowait(void) return sum; } -unsigned long nr_iowait_cpu(void) +unsigned long nr_iowait_cpu(int cpu) { - struct rq *this = this_rq(); + struct rq *this = cpu_rq(cpu); return atomic_read(&this->nr_iowait); } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 1d7b9bc..101e8aa 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -159,10 +159,12 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time) ktime_t delta; if (ts->idle_active) { + int cpu = get_cpu(); delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); - if (nr_iowait_cpu() > 0) + if (nr_iowait_cpu(cpu) > 0) ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta); + put_cpu(); ts->idle_entrytime = now; } -- 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/
From: Arjan van de Ven on 14 Jun 2010 23:40 On Mon, 14 Jun 2010 18:17:35 +0300 Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> wrote: > On (06/14/10 08:01), Arjan van de Ven wrote: > > > decided to patch nr_iowait_cpu instead. > > > > the bug is that it needs to be > > > > nr_iowait_cpu(int cpu) > > > > Something similar to this? yup that'll do it Acked-by: Arjan van de Ven <arjan(a)linux.intel.com> -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/
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