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charset="utf-8" Trace task's preemption due to a wakeups, getting delayed. Which can occurs when the running task requested extra time on cpu. Also, indicate the NEED_RESCHED flag set on the task getting cleared. Signed-off-by: Prakash Sangappa --- include/trace/events/sched.h | 28 ++++++++++++++++++++++++++++ kernel/entry/common.c | 8 ++++++-- 2 files changed, 34 insertions(+), 2 deletions(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 8994e97d86c1..4aa04044b14a 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -296,6 +296,34 @@ TRACE_EVENT(sched_migrate_task, __entry->orig_cpu, __entry->dest_cpu) ); =20 +/* + * Tracepoint for delayed resched requested by task: + */ +TRACE_EVENT(sched_delay_resched, + + TP_PROTO(struct task_struct *p, unsigned int resched_flg), + + TP_ARGS(p, resched_flg), + + TP_STRUCT__entry( + __array( char, comm, TASK_COMM_LEN ) + __field( pid_t, pid ) + __field( int, cpu ) + __field( int, flg ) + ), + + TP_fast_assign( + memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + __entry->pid =3D p->pid; + __entry->cpu =3D task_cpu(p); + __entry->flg =3D resched_flg; + ), + + TP_printk("comm=3D%s pid=3D%d cpu=3D%d resched_flg_cleared=3D0x%x", + __entry->comm, __entry->pid, __entry->cpu, __entry->flg) + +); + DECLARE_EVENT_CLASS(sched_process_template, =20 TP_PROTO(struct task_struct *p), diff --git a/kernel/entry/common.c b/kernel/entry/common.c index b26adccb32df..1951e6a4e9bc 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -12,6 +12,7 @@ =20 #include "common.h" =20 +#include #define CREATE_TRACE_POINTS #include =20 @@ -100,9 +101,12 @@ __always_inline unsigned long exit_to_user_mode_loop(s= truct pt_regs *regs, local_irq_enable_exit_to_user(ti_work); =20 if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)) { - if (irq && rseq_delay_resched()) + if (irq && rseq_delay_resched()) { clear_tsk_need_resched(current); - else + trace_sched_delay_resched(current, + ti_work & (_TIF_NEED_RESCHED | + _TIF_NEED_RESCHED_LAZY)); + } else schedule(); } =20 --=20 2.43.5