Messages in this thread |  | | | Date | Sat, 8 Dec 2007 16:33:27 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH] scheduler: fix x86 regression in native_sched_clock |
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* Michael Buesch <mb@bu3sch.de> wrote:
> On Saturday 08 December 2007 16:13:41 Ingo Molnar wrote: > > > > * Mark Lord <lkml@rtr.ca> wrote: > > > > > Ingo Molnar wrote: > > >> ... > > >> thanks. I do get the impression that most of this can/should wait until > > >> 2.6.25. The patches look quite dangerous. > > > .. > > > > > > I confess to not really trying hard to understand everything in this > > > thread, but the implication seems to be that this bug might affect > > > udelay() and possibly jiffies ? > > > > no, it cannot affect jiffies. (jiffies was a red herring all along) > > > > udelay() cannot be affected either - sched_clock() has no effect on > > udelay(). _But_, when there are TSC problems then tsc based udelay() > > suffers too so the phenomenons may _seem_ related. > > What about msleep()? I suspect problems in b43 because of this issue. > msleep() returning too early. Is that possible with this bug?
i cannot see how. You can verify msleep by running something like this:
while :; do time usleep 111000; done
you should see a steady stream of:
real 0m0.113s real 0m0.113s real 0m0.113s
(on an idle system). If it fluctuates, with occasional longer delays, there's some timer problem present.
Ingo
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