From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754456Ab1LVAP4 (ORCPT ); Wed, 21 Dec 2011 19:15:56 -0500 Received: from intmgw002.ash2.facebook.com ([66.220.155.179]:43870 "EHLO intmgw003.ash2.facebook.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752186Ab1LVAPw (ORCPT ); Wed, 21 Dec 2011 19:15:52 -0500 From: Arun Sharma To: linux-kernel@vger.kernel.org Cc: Arun Sharma , Peter Zijlstra , Steven Rostedt , Mathieu Desnoyers , Arnaldo Carvalho de Melo , Andrew Vagin , Frederic Weisbecker , Ingo Molnar Subject: [PATCH] tracing, sched: Add a new tracepoint for sleeptime Date: Wed, 21 Dec 2011 16:15:40 -0800 Message-Id: <1324512940-32060-2-git-send-email-asharma@fb.com> X-Mailer: git-send-email 1.7.4 In-Reply-To: <1324512940-32060-1-git-send-email-asharma@fb.com> References: <1324512940-32060-1-git-send-email-asharma@fb.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If CONFIG_SCHEDSTATS is defined, the kernel maintains information about how long the task was sleeping or in the case of iowait, blocking in the kernel before getting woken up. Note: this information is only provided for sched_fair. Other scheduling classes may choose to provide this in the future. Note: the delay includes the time spent on the runqueue as well. Signed-off-by: Arun Sharma Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Arnaldo Carvalho de Melo Cc: Andrew Vagin Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: linux-kernel@vger.kernel.org --- include/trace/events/sched.h | 50 ++++++++++++++++++++++++++++++++++++++++++ kernel/sched/core.c | 1 + kernel/sched/fair.c | 2 - 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 959ff18..3442c6d 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -363,6 +363,56 @@ TRACE_EVENT(sched_stat_runtime, (unsigned long long)__entry->vruntime) ); +#ifdef CREATE_TRACE_POINTS +static inline u64 trace_get_sleeptime(struct task_struct *tsk) +{ +#ifdef CONFIG_SCHEDSTATS + u64 block, sleep; + + block = tsk->se.statistics.block_start; + sleep = tsk->se.statistics.sleep_start; + tsk->se.statistics.block_start = 0; + tsk->se.statistics.sleep_start = 0; + + return block ? block : sleep ? sleep : 0; +#else + return 0; +#endif +} +#endif + +/* + * Tracepoint for accounting sleeptime (time the task is sleeping + * or waiting for I/O). + */ +TRACE_EVENT(sched_stat_sleeptime, + + TP_PROTO(struct task_struct *tsk, u64 now), + + TP_ARGS(tsk, now), + + TP_STRUCT__entry( + __array( char, comm, TASK_COMM_LEN ) + __field( pid_t, pid ) + __field( u64, sleeptime ) + ), + + TP_fast_assign( + memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN); + __entry->pid = tsk->pid; + __entry->sleeptime = trace_get_sleeptime(tsk); + __entry->sleeptime = __entry->sleeptime ? + now - __entry->sleeptime : 0; + ) + TP_perf_assign( + __perf_count(__entry->sleeptime); + ), + + TP_printk("comm=%s pid=%d sleeptime=%Lu [ns]", + __entry->comm, __entry->pid, + (unsigned long long)__entry->sleeptime) +); + /* * Tracepoint for showing priority inheritance modifying a tasks * priority. diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ca8fd44..172e6ee 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1899,6 +1899,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) local_irq_enable(); #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ finish_lock_switch(rq, prev); + trace_sched_stat_sleeptime(current, rq->clock); fire_sched_in_preempt_notifiers(current); if (mm) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cd3b642..86deb3b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1003,7 +1003,6 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) if (unlikely(delta > se->statistics.sleep_max)) se->statistics.sleep_max = delta; - se->statistics.sleep_start = 0; se->statistics.sum_sleep_runtime += delta; if (tsk) { @@ -1020,7 +1019,6 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) if (unlikely(delta > se->statistics.block_max)) se->statistics.block_max = delta; - se->statistics.block_start = 0; se->statistics.sum_sleep_runtime += delta; if (tsk) { -- 1.7.4