Messages in this thread | | | Date | Thu, 26 Jul 2012 23:01:07 +0100 | From | Ben Hutchings <> | Subject | Re: [ 028/108] sched/nohz: Rewrite and fix load-avg computation -- again |
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On Thu, Jul 26, 2012 at 11:25:37PM +0200, Peter Zijlstra wrote: > On Tue, 2012-07-24 at 15:06 +0100, Ben Hutchings wrote: > > On Mon, 2012-07-23 at 02:07 +0100, Ben Hutchings wrote: > > > 3.2-stable review patch. If anyone has any objections, please let me know. > > > > > > ------------------ > > > > > > From: Peter Zijlstra <a.p.zijlstra@chello.nl> > > > > > > commit 5167e8d5417bf5c322a703d2927daec727ea40dd upstream. > > > > > > Thanks to Charles Wang for spotting the defects in the current code: > > > > > > - If we go idle during the sample window -- after sampling, we get a > > > negative bias because we can negate our own sample. > > > > > > - If we wake up during the sample window we get a positive bias > > > because we push the sample to a known active period. > > > > > > So rewrite the entire nohz load-avg muck once again, now adding > > > copious documentation to the code. > > [...] > > > > Based on <http://bugs.debian.org/674153>, I think we also need: > > > > 556061b sched/nohz: Fix rq->cpu_load[] calculations > > 5aaa0b7 sched/nohz: Fix rq->cpu_load calculations some more > > > > Does this ('sched/nohz: Rewrite and fix load-avg computation -- again') > > depend in any way on those, or are they separate fixes? > > they might touch on a few entry points but the logic is separate. > > ->cpu_load[] is per-cpu weight tracking for the load-balancer.
That's what I thought, so I went ahead with just the one. Should I queue up the other two for a future 3.2.y update?
Ben.
-- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus
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