Messages in this thread | | | Date | Wed, 11 May 2016 08:53:05 +0800 | Subject | Re: PROBLEM: Scheduling latency not respected in CFS with HRTICK enabled | From | Wanpeng Li <> |
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2016-05-06 23:43 GMT+08:00 Tomasz Grabiec <tgrabiec@scylladb.com>: [...] > prev_comm=python prev_pid=873 prev_prio=120 prev_state=R ==> > next_comm=python next_pid=874 next_prio=120 > python 874 [002] 3273334.932741: probe:hrtick: (ffffffff8109b430) > python 874 [002] 3273334.932742: sched:sched_stat_runtime: > comm=python pid=874 runtime=503174 [ns] vruntime=1549788942230752 [ns]
hrtick fire after almost 0.5ms(the time slice process 874 get).
> python 874 [002] 3273334.932743: sched:sched_stat_runtime: > comm=python pid=874 runtime=948 [ns] vruntime=1549788942231700 [ns] > python 874 [002] 3273334.936240: probe:scheduler_tick: (ffffffff810a1f30) > python 874 [002] 3273334.936241: sched:sched_stat_runtime: > comm=python pid=874 runtime=3497530 [ns] vruntime=1549788945729230 > [ns]
continue to run another 3.4ms until next normal scheduler tick fire.
> python 874 [002] 3273334.936249: sched:sched_stat_runtime: > comm=python pid=874 runtime=8553 [ns] vruntime=1549788945737783 [ns] > python 874 [002] 3273334.936250: sched:sched_stat_wait: > comm=python pid=873 delay=4010205 [ns] > python 874 [002] 3273334.936250: probe:hrtick_start: (ffffffff8109f4f0) > python 874 [002] 3273334.936251: sched:sched_switch: > prev_comm=python prev_pid=874 prev_prio=120 prev_state=R ==> > next_comm=python next_pid=873 next_prio=120
So the process 874 continue to run util next scheduler fick event if hrtick has already fired. I think Peterz can give any light.
Ping Peterz :-)
Regards, Wanpeng Li
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