Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [PATCH] sched/fair: Fix overutilized update in enqueue_task_fair() | Date | Thu, 12 Nov 2020 12:52:18 +0000 |
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On 12/11/20 12:38, Quentin Perret wrote: > On Thursday 12 Nov 2020 at 12:29:59 (+0000), Valentin Schneider wrote: >> Alternatively: how much does not updating the overutilized status here help >> us? The next tick will unconditionally update it, which for arm64 is >> anywhere in the next ]0, 4]ms. That "fake" fork-time util_avg should already >> be accounted in the rq util_avg, and even if the new task was running the >> entire time, 4ms doesn't buy us much decay. > > Yes, this is arguably a dodgy hack, which will not save us in a number > of cases. The only situation where this helps is for short-lived tasks > that will run only once. And this is a sadly common programming pattern. > > So yeah, this is not the prettiest thing in the world, but it doesn't > cost us much and helps some real-world workloads, so ... >
Aye aye
> Thanks, > Quentin
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