Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754151Ab0GAHHn (ORCPT ); Thu, 1 Jul 2010 03:07:43 -0400 Received: from casper.infradead.org ([85.118.1.10]:34983 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020Ab0GAHHl convert rfc822-to-8bit (ORCPT ); Thu, 1 Jul 2010 03:07:41 -0400 Subject: [PATCH] sched: Cure nr_iowait_cpu() users From: Peter Zijlstra To: Andrew Morton Cc: Sergey Senozhatsky , Arjan van de Ven , "Rafael J. Wysocki" , Maxim Levitsky , Len Brown , Pavel Machek , Jiri Slaby , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar In-Reply-To: <20100630125853.245e6b99.akpm@linux-foundation.org> References: <20100614140941.GA3581@swordfish.minsk.epam.com> <20100614073853.6fa2f91f@infradead.org> <20100614145439.GA3448@swordfish.minsk.epam.com> <20100614080154.7d6a71fc@infradead.org> <20100614151735.GB3448@swordfish.minsk.epam.com> <20100614204021.52c50cdc@infradead.org> <20100615061927.GA3312@swordfish> <20100615072435.5a47d850@infradead.org> <20100615145029.GB3967@swordfish.minsk.epam.com> <20100615080808.6286448b@infradead.org> <20100617062950.GA3979@swordfish> <1277476773.32034.639.camel@twins> <20100630125853.245e6b99.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 01 Jul 2010 09:07:17 +0200 Message-ID: <1277968037.1868.120.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4649 Lines: 146 With 0224cf4c5e (sched: Intoduce get_cpu_iowait_time_us()) Arjan broke things by not making sure preemption was indeed disabled by the callers of nr_iowait_cpu() which took the iowait value of the current cpu. This resulted in a heap of preempt warnings. Cure this by making nr_iowait_cpu() take a cpu number and fix up the callers to pass in the right number. Signed-off-by: Peter Zijlstra --- Confirmed to work.. drivers/cpuidle/governors/menu.c | 4 ++-- include/linux/sched.h | 2 +- kernel/sched.c | 4 ++-- kernel/time/tick-sched.c | 16 ++++++++-------- 4 files changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 52ff8aa..1b12870 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -143,7 +143,7 @@ static inline int which_bucket(unsigned int duration) * This allows us to calculate * E(duration)|iowait */ - if (nr_iowait_cpu()) + if (nr_iowait_cpu(smp_processor_id())) bucket = BUCKETS/2; if (duration < 10) @@ -175,7 +175,7 @@ static inline int performance_multiplier(void) mult += 2 * get_loadavg(); /* for IO wait tasks (per cpu!) we add 5x each */ - mult += 10 * nr_iowait_cpu(); + mult += 10 * nr_iowait_cpu(smp_processor_id()); return mult; } diff --git a/include/linux/sched.h b/include/linux/sched.h index a61c08c..1f25798 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 71e3dc8..d3c0262 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2946,9 +2946,9 @@ 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 e0707ea..17525ca 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -154,14 +154,14 @@ static void tick_nohz_update_jiffies(ktime_t now) * Updates the per cpu time idle statistics counters */ static void -update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time) +update_ts_time_stats(int cpu, struct tick_sched *ts, ktime_t now, u64 *last_update_time) { ktime_t delta; if (ts->idle_active) { 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); ts->idle_entrytime = now; } @@ -175,19 +175,19 @@ static void tick_nohz_stop_idle(int cpu, ktime_t now) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); - update_ts_time_stats(ts, now, NULL); + update_ts_time_stats(cpu, ts, now, NULL); ts->idle_active = 0; sched_clock_idle_wakeup_event(0); } -static ktime_t tick_nohz_start_idle(struct tick_sched *ts) +static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts) { ktime_t now; now = ktime_get(); - update_ts_time_stats(ts, now, NULL); + update_ts_time_stats(cpu, ts, now, NULL); ts->idle_entrytime = now; ts->idle_active = 1; @@ -216,7 +216,7 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) if (!tick_nohz_enabled) return -1; - update_ts_time_stats(ts, ktime_get(), last_update_time); + update_ts_time_stats(cpu, ts, ktime_get(), last_update_time); return ktime_to_us(ts->idle_sleeptime); } @@ -242,7 +242,7 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time) if (!tick_nohz_enabled) return -1; - update_ts_time_stats(ts, ktime_get(), last_update_time); + update_ts_time_stats(cpu, ts, ktime_get(), last_update_time); return ktime_to_us(ts->iowait_sleeptime); } @@ -284,7 +284,7 @@ void tick_nohz_stop_sched_tick(int inidle) */ ts->inidle = 1; - now = tick_nohz_start_idle(ts); + now = tick_nohz_start_idle(cpu, ts); /* * If this cpu is offline and it is the one which updates -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/