Messages in this thread | | | Date | Mon, 1 Aug 2022 15:26:39 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] sched/fair: no sync wakeup from interrupt context |
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* K Prateek Nayak <kprateek.nayak@amd.com> wrote:
> Hello Libo and Peter, > > tl;dr > > - We observed a major regression with tbench when testing the latest tip > sched/core at: > commit 14b3f2d9ee8d "sched/fair: Disallow sync wakeup from interrupt context" > Reason for the regression are the fewer affine wakeups that leaves the > client farther away from the data it needs to consume next primed in the > waker's LLC. > Such regressions can be expected from tasks that use sockets to communicate > significant amount of data especially on system with multiple LLCs. > > - Other benchmarks have a comparable behavior to the tip at previous commit > commit : 91caa5ae2424 "sched/core: Fix the bug that task won't enqueue > into core tree when update cookie" > > I'll leave more details below.
Mel Gorman also warned about this negative side-effect in:
Subject: Re: [PATCH] sched/fair: no sync wakeup from interrupt context Date: Fri, 15 Jul 2022 11:07:38 +0100 Message-ID: <20220715100738.GD3493@suse.de>
https://lore.kernel.org/all/20220715100738.GD3493@suse.de/
I've reverted this commit (14b3f2d9ee8df3b) for the time being from tip:sched/core.
Thanks for the heads-up!
Thanks,
Ingo
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