We want to measure the latency of RT tasks in our production environment with schedstat facility, but currently schedstat is only supported for fair sched class. This patchset enable it for RT sched class as well. The schedstat statistics are defined in struct sched_entity, which is a member of struct task_struct, so we can resue it for RT sched class. The schedstat usage in RT sched class is similar with fair sched class, for example, fair RT enqueue update_stats_enqueue_fair update_stats_enqueue_rt dequeue update_stats_dequeue_fair update_stats_dequeue_rt put_prev_task update_stats_wait_start update_stats_wait_start set_next_task update_stats_wait_end update_stats_wait_end show /proc/[pid]/sched /proc/[pid]/sched The sched:sched_stats_* tracepoints can be used to trace RT tasks as well after that patchset. PATCH #1 ~ #3 are the preparation of PATCH #4. Yafang Shao (4): sched: define task_of() as a common helper sched: make schedstats helpers not depend on cfs_rq sched: define update_stats_curr_start() as a common helper sched, rt: support schedstat for RT sched class kernel/sched/fair.c | 173 ++----------------------------------------- kernel/sched/rt.c | 63 +++++++++++++++- kernel/sched/sched.h | 23 ++++++ kernel/sched/stats.c | 134 +++++++++++++++++++++++++++++++++ kernel/sched/stats.h | 11 +++ 5 files changed, 236 insertions(+), 168 deletions(-) -- 2.18.4
