Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755876AbaFZJRc (ORCPT ); Thu, 26 Jun 2014 05:17:32 -0400 Received: from fgwmail2.fujitsu.co.jp ([164.71.1.135]:57614 "EHLO fgwmail2.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753430AbaFZJRb (ORCPT ); Thu, 26 Jun 2014 05:17:31 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <53ABE50F.3040900@jp.fujitsu.com> Date: Thu, 26 Jun 2014 18:17:03 +0900 From: Hidetoshi Seto User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Fernando Luis Vazquez Cao , Tetsuo Handa , Frederic Weisbecker , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Andrew Morton , Arjan van de Ven , Oleg Nesterov , Preeti U Murthy , Denys Vlasenko Subject: [PATCH 8/8] cputime: iowait aware idle tick accounting References: <53ABE28F.6010402@jp.fujitsu.com> In-Reply-To: <53ABE28F.6010402@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By changes in vtime* codes by previous patches, now account_idle_time() become a function to be called only from tick-accounting codes. Introduce __account_idle_ticks() to do iowait accounting in ticks properly. For this purpose record jiffies at end of iowait. Not-Tested-by: Hidetoshi Seto --- include/linux/kernel_stat.h | 1 + kernel/sched/core.c | 1 + kernel/sched/cputime.c | 68 +++++++++++++++++++++++++++++------------- kernel/sched/sched.h | 1 + 4 files changed, 50 insertions(+), 21 deletions(-) diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index ecbc52f..bdea2f7 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -85,6 +85,7 @@ extern unsigned long long task_delta_exec(struct task_struct *); extern void account_user_time(struct task_struct *, cputime_t, cputime_t); extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t); extern void account_steal_time(cputime_t); +extern void account_iowait_time(cputime_t); extern void account_idle_time(cputime_t); #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f8eec61..5d3ebc3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4347,6 +4347,7 @@ static inline void iowait_stop(struct rq *rq) if (!rq->nr_iowait && rq != this_rq()) { vtime_iowait_exit(rq->cpu); rq->last_iowait = ktime_get(); + rq->last_iowait_jiffies = jiffies; } raw_spin_unlock(&rq->iowait_lock); } diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 866a3ff..42a0e99 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -240,40 +240,65 @@ void account_steal_time(cputime_t cputime) } /* + * Account for iowait time. + * @cputime: the cpu time spent in io wait + */ +void account_iowait_time(cputime_t cputime) +{ + u64 *cpustat = kcpustat_this_cpu->cpustat; + + cpustat[CPUTIME_IOWAIT] += (__force u64) cputime; +} + +/* + * Account for idle time. + * @cputime: the cpu time spent in idle wait + */ +void account_idle_time(cputime_t cputime) +{ + u64 *cpustat = kcpustat_this_cpu->cpustat; + + cpustat[CPUTIME_IDLE] += (__force u64) cputime; +} + +/* * Account for idle and iowait time in a dulation. * @idle_enter: time stamp at idle entry * @iowait_exit: time stamp when nr_iowait dropped to 0 * @idle_exit: time stamp at idle exit */ -void account_idle_and_iowait(cputime_t idle_enter, cputime_t iowait_exit, cputime_t idle_exit) +void account_idle_and_iowait(cputime_t idle_enter, cputime_t iowait_exit, + cputime_t idle_exit) { - u64 *cpustat = kcpustat_this_cpu->cpustat; struct rq *rq = this_rq(); if (rq->nr_iowait > 0 || iowait_exit > idle_exit) { - cpustat[CPUTIME_IOWAIT] += (__force u64) idle_exit - idle_enter; + account_iowait_time(idle_exit - idle_enter); } else if (iowait_exit > idle_enter) { - cpustat[CPUTIME_IOWAIT] += (__force u64) iowait_exit - idle_enter; - cpustat[CPUTIME_IDLE] += (__force u64) idle_exit - iowait_exit; + account_iowait_time(iowait_exit - idle_enter); + account_idle_time(idle_exit - iowait_exit); } else { - cpustat[CPUTIME_IDLE] += (__force u64) idle_exit - idle_enter; + account_idle_time(idle_exit - idle_enter); } } /* - * Account for idle time. - * @cputime: the cpu time spent in idle wait (sometimes include iowait time) + * Account for idle and iowait time. + * @ticks: ticks spent in idle/io wait */ -void account_idle_time(cputime_t cputime) +static void __account_idle_ticks(int ticks) { - u64 *cpustat = kcpustat_this_cpu->cpustat; struct rq *rq = this_rq(); + unsigned long no_io_ticks = jiffies - rq->last_iowait_jiffies; - /* FIXME */ - if (rq->nr_iowait > 0) - cpustat[CPUTIME_IOWAIT] += (__force u64) cputime; - else - cpustat[CPUTIME_IDLE] += (__force u64) cputime; + if (rq->nr_iowait > 0) { + account_iowait_time(jiffies_to_cputime(ticks)); + } else if (no_io_ticks < ticks) { + account_iowait_time(jiffies_to_cputime(ticks - no_io_ticks)); + account_idle_time(jiffies_to_cputime(no_io_ticks)); + } else { + account_idle_time(jiffies_to_cputime(ticks)); + } } static __always_inline bool steal_account_process_tick(void) @@ -380,11 +405,11 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, } else if (user_tick) { account_user_time(p, cputime, scaled); } else if (p == rq->idle) { - account_idle_time(cputime); + __account_idle_ticks(ticks); } else if (p->flags & PF_VCPU) { /* System time or guest time */ account_guest_time(p, cputime, scaled); } else { - __account_system_time(p, cputime, scaled, CPUTIME_SYSTEM); + __account_system_time(p, cputime, scaled, CPUTIME_SYSTEM); } } @@ -396,7 +421,8 @@ static void irqtime_account_idle_ticks(int ticks) } #else /* CONFIG_IRQ_TIME_ACCOUNTING */ static inline void irqtime_account_idle_ticks(int ticks) {} -static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick, +static inline void irqtime_account_process_tick(struct task_struct *p, + int user_tick, struct rq *rq, int nr_ticks) {} #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ @@ -499,7 +525,7 @@ void account_process_tick(struct task_struct *p, int user_tick) account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, one_jiffy_scaled); else - account_idle_time(cputime_one_jiffy); + __account_idle_ticks(1); } /* @@ -514,7 +540,7 @@ void account_steal_ticks(unsigned long ticks) /* * Account multiple ticks of idle time. - * @ticks: number of stolen ticks + * @ticks: number of idle ticks */ void account_idle_ticks(unsigned long ticks) { @@ -524,7 +550,7 @@ void account_idle_ticks(unsigned long ticks) return; } - account_idle_time(jiffies_to_cputime(ticks)); + __account_idle_ticks(ticks); } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4ddfddc..e5fb7b5 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -564,6 +564,7 @@ struct rq { raw_spinlock_t iowait_lock ____cacheline_aligned; unsigned int nr_iowait; ktime_t last_iowait; + unsigned long last_iowait_jiffies; #ifdef CONFIG_SMP struct root_domain *rd; -- 1.7.1 -- 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/