From b20490aa50898338c4e7936e32c4a3a19cc3db11 Mon Sep 17 00:00:00 2001 From: Lingutla Chandrasekhar Date: Fri, 1 Mar 2019 17:17:09 +0530 Subject: [PATCH] FROMLIST: trace: Add trace points for tasklet entry/exit Tasklets are supposed to finish their work quickly and should not block the current running process, but it is not guaranteed that. Currently softirq_entry/exit can be used to know total tasklets execution time, but not helpful to track individual tasklet's execution time. With that we can't find any culprit tasklet function, which is taking more time. Add tasklet_entry/exit trace point support to track individual tasklet execution. This patch has been carried in the Android tree for awhile so I wanted to submit it for review upstream. Feedback would be appreciated! Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Thomas Gleixner Cc: "Paul E. McKenney" Cc: Connor O'Brien Cc: kernel-team@android.com Signed-off-by: Lingutla Chandrasekhar [elavila: Port to android-mainline] Signed-off-by: J. Avila [jstultz: Rebased to upstream, cut unused trace points, added comments for the tracepoints, reworded commit] Signed-off-by: John Stultz Link: https://lore.kernel.org/lkml/20221213185310.1315794-1-jstultz@google.com/ Bug: 168521633 Change-Id: I3944fcedffae54a5f761d0b18ff1c41d2c3e4aeb --- include/trace/events/irq.h | 43 ++++++++++++++++++++++++++++++++++++++ kernel/softirq.c | 9 ++++++-- 2 files changed, 50 insertions(+), 2 deletions(-) diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h index eeceafaaea4c..da85851d4ec1 100644 --- a/include/trace/events/irq.h +++ b/include/trace/events/irq.h @@ -160,6 +160,49 @@ DEFINE_EVENT(softirq, softirq_raise, TP_ARGS(vec_nr) ); +DECLARE_EVENT_CLASS(tasklet, + + TP_PROTO(void *func), + + TP_ARGS(func), + + TP_STRUCT__entry( + __field( void *, func) + ), + + TP_fast_assign( + __entry->func = func; + ), + + TP_printk("function=%ps", __entry->func) +); + +/** + * tasklet_entry - called immediately before the tasklet is run + * @func: tasklet callback or function being run + * + * Used to find individual tasklet execution time + */ +DEFINE_EVENT(tasklet, tasklet_entry, + + TP_PROTO(void *func), + + TP_ARGS(func) +); + +/** + * tasklet_exit - called immediately after the tasklet is run + * @func: tasklet callback or function being run + * + * Used to find individual tasklet execution time + */ +DEFINE_EVENT(tasklet, tasklet_exit, + + TP_PROTO(void *func), + + TP_ARGS(func) +); + #endif /* _TRACE_IRQ_H */ /* This part must be outside protection */ diff --git a/kernel/softirq.c b/kernel/softirq.c index 411491a6f7d7..eb6d0821bc8c 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -838,10 +838,15 @@ static void tasklet_action_common(struct softirq_action *a, if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { if (tasklet_clear_sched(t)) { - if (t->use_callback) + if (t->use_callback) { + trace_tasklet_entry(t->callback); t->callback(t); - else + trace_tasklet_exit(t->callback); + } else { + trace_tasklet_entry(t->func); t->func(t->data); + trace_tasklet_exit(t->func); + } } tasklet_unlock(t); continue;