Messages in this thread | | | Date | Wed, 31 Dec 2008 23:38:01 +0100 | From | "Fabio Comolli" <> | Subject | Re: large intermittent latency spike 2.6.28 (and 2.6.27.10), bisect commit ca7e716c7833aeaeb8fedd6d004c5f5d5e14d325 -> Revert "sched_clock: prevent scd->clock from moving backwards" |
| |
The revert you did was rejected in the 2.6.28 timeframe becaused it caused a regression on my laptop. The patch Ingo suggested (originally from Thomas Gleixner) addresses both your issue and mine.
Regards, Fabio
On Wed, Dec 31, 2008 at 11:27 PM, Jayson King <dev@jaysonking.com> wrote: > Arjan van de Ven wrote: >> Jayson King <dev@jaysonking.com> wrote: >>> Please disregard this. ... >> >> can you run latencytop to see if it can pinpoint a cause of latency? > > Like I said in my other reply I was running the wrong kernel when I wrote > that (oops)... So now I am still sure it is ca7e716. > > Ingo's patch makes the same change that reverting ca7e716 does here: > > - max_clock = scd->tick_gtod + TICK_NSEC; > + max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC); > > > And with that change (I'm using Ingo's patch now) I can't trigger the hang > anymore. And before, I could reliably trigger it in a short time. > > Jayson > >
| |