Messages in this thread | | | Date | Thu, 4 Jul 2013 22:27:19 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [URGENT rfc patch 0/3] tsc clocksource bug fix |
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On Thu, 4 Jul 2013, Davidlohr Bueso wrote:
> On Thu, 2013-07-04 at 13:00 +0200, Thomas Gleixner wrote: > > On Thu, 4 Jul 2013, Alex Shi wrote: > > > > > We find some benchmarks drop a lot on tip/sched/core on many Intel boxes, > > > like oltp, tbench, hackbench etc. and bisected the commit 5d33b883ae > > > cause this regression. Due to this commit, the clocksource was changed > > > to hpet from tsc even tsc will be set CLOCK_SOURCE_VALID_FOR_HRES later > > > in clocksource_watchdog. > > > > 5d33b883ae is not in tip/sched/core. So what are you testing and > > bisecting? > > I think he's referring to: > > commit 5d33b883aed81c6fbcd09c6f7c3619eee850a7e2
I know what he is referring to. He explicitly mentions this commit:
> > > like oltp, tbench, hackbench etc. and bisected the commit 5d33b883ae
What I was pointing out that he was referring to tip sched/core at the same time
> > > We find some benchmarks drop a lot on tip/sched/core on many Intel boxes,
And that branch does NOT have that commit included. So how can you see a regression on a branch caused by a commit NOT included into that branch?
The offending commit is in tip timers/core and not in tip sched/core. What I'm wanted to say is, that we need a proper description of problems and not some random association.
It tricked you to assume, that I'm not able to figure it out myself :)
See? These things are complex and subtle, so we need precise descriptions and not some sloppy semi correct data.
I'm well aware of the issue and with Peters help I got a reasonable explanation for it. A proper fix is about to be sent out.
Thanks,
tglx
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