Messages in this thread | | | Date | Thu, 30 Mar 2017 14:51:58 +0200 | From | Frederic Weisbecker <> | Subject | Re: [BUG nohz]: wrong user and system time accounting |
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On Thu, Mar 30, 2017 at 06:27:31AM +0200, Mike Galbraith wrote: > On Wed, 2017-03-29 at 16:08 -0400, Rik van Riel wrote: > > > A random offset, or better yet a somewhat randomized > > tick length to make sure that simultaneous ticks are > > fairly rare and the vtime sampling does not end up > > "in phase" with the jiffies incrementing, could make > > the accounting work right again. > > That improves jitter, especially on big boxen. I have an 8 socket box > that thinks it's an extra large PC, there, collision avoidance matters > hugely. I couldn't reproduce bean counting woes, no idea if collision > avoidance will help that.
Out of curiosity, where is the main contention between ticks? I indeed know some locks that can be taken on special cases, such as posix cpu timers.
Also, why does it raise power consumption issues?
Thanks.
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