Messages in this thread | | | Date | Sun, 7 Nov 2021 16:56:16 +0100 | From | Frederic Weisbecker <> | Subject | Re: Performance regression: thread wakeup time (latency) increased up to 3x |
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Hi Norbert,
On Tue, Oct 19, 2021 at 12:01:32AM -0700, Norbert wrote: > > On the thought that it might enter deeper idle/wait/sleep states: > > The benchmark executes this test in a quite tight loop, except that so far > it waited 1000 ns (with a mix of pause and rdtsc) before calling futex-wake, > to make sure the other thread fully enters the futex-wait without taking any > shortcuts. > > Except when this "prepare time" is reduced to less than even 350 ns or so, > the timings remain the same (they go up before they start going down). > Surely in this situation the thread is at least not supposed to enter deeper > states for such short waiting times.
Is it possible for you to share this benchmark so that I can try to reproduce?
Thanks!
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