[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-kernel
Subject:    Re: [PATCHSET] Announce: High-res timers, tickless/dyntick and dynamic HZ -V4
From:       Pavel Machek <pavel () ucw ! cz>
Date:       2006-06-30 21:09:22
Message-ID: 20060630210922.GA1717 () elf ! ucw ! cz
[Download RAW message or body]

Hi!

> > > > I briefly tested -dyntick5 on my thinkpad, and it seems to work
> > > > okay... but timer still seems to tick at 250Hz.
> > > 
> > > > ...am I doing something wrong?
> > > 
> > > can you send me the bootlog and your .config file please ?
> > 
> > ...attached. (I do not have to enable anything in sysfs/commandline to
> > enable noidlehz, right?).
> 
> Right. 
> 
> You trapped into the no apic on SMP trap. I did not come around to fix
> that yet. What happens that you don't have lapic on the commandline and
> BIOS has lapic disabled. Therefor Linux switches to IPI broadcasting if
> the PIT interrupt, which does not work with idle_hz and highres timer as
> those are per cpu. I will fix that for SMP kernels which bring up only
> one CPU.
> 
> You can work around that for now by either using an UP kernel or
> enabling local APIC, which is recommended anyway because the APIC timer
> is faster to access and has longer max time than PIT.

Thanks, it works okay with UP kernel.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
[prev in list] [next in list] [prev in thread] [next in thread]