Re: bisected: futex regression >= 3.14 - was - Slowdown due to threads bouncing between HT cores

From: Steinar H. Gunderson
Date: Wed Oct 08 2014 - 13:05:25 EST


On Wed, Oct 08, 2014 at 01:04:01PM -0400, Linus Torvalds wrote:
> So like Thomas, I would suspect a race condition in the futex use, and
> then the exact futex implementation details are just exposing it
> incidentally.

FWIW, Stockfish does not use futex directly; it uses pthreads (or Win32
threads if you are on that OS :-) ). That doesn't preclude a race condition
somewhere, of course.

/* Steinar */
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