Messages in this thread | | | Date | Wed, 12 Apr 2023 11:10:43 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH v4] sched: Fix performance regression introduced by mm_cid |
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On Tue, Apr 11, 2023 at 09:12:21PM +0800, Aaron Lu wrote:
> Forget about this "v4 is better than v2 and v3" part, my later test > showed the contention can also rise to around 18% for v4.
So while I can reproduce the initial regression on a HSW-EX system (4*18*2) and get lovely things like:
34.47%--schedule_hrtimeout_range_clock schedule | --34.42%--__schedule | |--31.86%--_raw_spin_lock | | | --31.65%--native_queued_spin_lock_slowpath | --0.72%--dequeue_task_fair | --0.60%--dequeue_entity
On a --threads=144 run; it is completely gone when I use v4:
6.92%--__schedule | |--2.16%--dequeue_task_fair | | | --1.69%--dequeue_entity | | | |--0.61%--update_load_avg | | | --0.54%--update_curr | |--1.30%--pick_next_task_fair | | | --0.54%--set_next_entity | |--0.77%--psi_task_switch | --0.69%--switch_mm_irqs_off
:-(
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