Re: [patch] fix the softlockup watchdog to actually work

From: Ingo Molnar
Date: Thu Jul 19 2007 - 10:51:31 EST



* Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> Hm, or more specifically, why would that be a problem for softlockup?
> Do you mean it doesn't measure time during ACPI idle? That would just
> make it trigger later than it would otherwise.

no, the return value after idling can be completely random on some
boxes, on a 64-bit scale - triggering the softlockup watchdog randomly.
(some boxes return random TSC values, etc.) Again, it's fine for the
scheduler's purpose, that's why i named it sched_clock().

the proper clocksource use within the kernel is ktime_get() [or
ktime_get_ts()]. Do not abuse sched_clock() for such things.

Ingo
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