Messages in this thread | | | Date | Sun, 23 Jul 2006 14:08:29 +0200 | Subject | Re: REGRESSION: the new i386 timer code fails to sync CPUs | From | Matthias Urlichs <> |
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Hi,
Andrew Morton: > - CPU0 and CPU1 share a TSC and CPU2 and CPU3 share another TSC. > That mmakes sense, since they're one dual-core Xeon each.
> - Earlier kernels didn't use the TSC as a time source whereas this one > does, hence the problems which you're observing. > Correct; see below.
> I assume that booting with clock=pit or clock=pmtmr fixes it? > Testing... yes, both.
> It would be useful to check your 2.6.17 boot logs, see if we can work out > what 2.6.17 was using for a clock source. > That's easy:
2.6.17 -Using pmtmr for high-res timesource 2.6.18git +Time: tsc clocksource has been installed.
I missed those two lines, as in the boot logs they're not really adjacent, so they got lost in the jumble of other differences.
Interestingly, CPU0/1 gets 6000 bogomips while CPU2/3 only reaches 5600 ..? (That happens with both kernels.) I do wonder why, and whether this has any bearing on the current problem.
-- Matthias Urlichs | {M:U} IT Design @ m-u-it.de | smurf@smurf.noris.de Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de - - BEANS ARE NEITHER FRUIT NOR MUSICAL -- Bart Simpson on chalkboard in episode 1F22 - 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/
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