Messages in this thread | | | Date | Wed, 20 Oct 2010 15:27:32 +0200 | From | Damien Wyart <> | Subject | Re: High CPU load when machine is idle (related to PROBLEM: Unusually high load average when idle in 2.6.35, 2.6.35.1 and later) |
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> > With 2.6.36-rc6, I'm seeing a load of around 0.60 when the machine > > is completely idle. This is similar to what someone reported for the > > latest 2.6.35.x stables. This is on a core i7 machine, but I've no > > time to bisect or test earlier versions right now, but I guess this > > is easy to reproduce on the same plateform.
> After further investigation and cross-checking with the thread "PROBLEM: > Unusually high load average when idle in 2.6.35, 2.6.35.1 and later", > I came to the following results:
> - the commit 74f5187ac873042f502227701ed1727e7c5fbfa9 isolated by Tim > seems to be the culprit; > - reverting it solves the problem with 2.6.36-rc7 in NOHZ mode: the load > when idle goes down to 0.00 (which it never does with the patch > applied)
In fact, after several hours of uptime, I also came into a situation of the load being around 0.80 or 0.60 when idle with the commit reverted. So IMHO, just reverting is not a better option than keeping the offending commit, and a real rework of the code is needed to clean up the situation.
Should'nt we enlarge the list of CC, because for now, responsivity has been close to 0 and it seems we will get a 2.6.36 with buggy load avg calculation. Even if it is only statistics, many supervision tools rely on the load avg, so for production environments, this is not a good thing.
Best, -- Damien
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