From 8a1dd1e547c1a037692e7a6da6a76108108c72b1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 17 May 2023 17:02:09 -1000 Subject: workqueue: Track and monitor per-workqueue CPU time usage Now that wq_worker_tick() is there, we can easily track the rough CPU time consumption of each workqueue by charging the whole tick whenever a tick hits an active workqueue. While not super accurate, it provides reasonable visibility into the workqueues that consume a lot of CPU cycles. wq_monitor.py is updated to report the per-workqueue CPU times. v2: wq_monitor.py was using "cputime" as the key when outputting in json format. Use "cpu_time" instead for consistency with other fields. Signed-off-by: Tejun Heo --- kernel/workqueue.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4ca66384d288..ee16ddb0647c 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -212,6 +212,7 @@ struct worker_pool { enum pool_workqueue_stats { PWQ_STAT_STARTED, /* work items started execution */ PWQ_STAT_COMPLETED, /* work items completed execution */ + PWQ_STAT_CPU_TIME, /* total CPU time consumed */ PWQ_STAT_CPU_INTENSIVE, /* wq_cpu_intensive_thresh_us violations */ PWQ_STAT_CM_WAKEUP, /* concurrency-management worker wakeups */ PWQ_STAT_MAYDAY, /* maydays to rescuer */ @@ -1136,6 +1137,8 @@ void wq_worker_tick(struct task_struct *task) if (!pwq) return; + pwq->stats[PWQ_STAT_CPU_TIME] += TICK_USEC; + /* * If the current worker is concurrency managed and hogged the CPU for * longer than wq_cpu_intensive_thresh_us, it's automatically marked -- cgit v1.2.3