* Jeremy Fitzhardinge <[EMAIL PROTECTED]> wrote: > Ingo Molnar wrote: > > Subject: softlockup: fix Xen bogosity > > From: Ingo Molnar <[EMAIL PROTECTED]> > > > > this Xen related commit: > > > > Well, not just Xen. It relates to any virtual environment: kvm, > lguest, vmi, xen... (Not that they all implement a measure of > unstolen time.) > > How about a more descriptive patch title, along the lines of > "softlockup watchdog: fix rate limiting"?
uhm, the problem was that it did not work _at all_, not something about 'rate limiting'. Yes, i got quite a bit grumpy when i found this, because you completely broke the softlockup watchdog via a pretty intrusive commit and you apparently didnt even do a minimal check whether its functionality was preserved! Updated patch for Andrew/Linus and for -stable attached. Ingo -----------------------------> Subject: fix the softlockup watchdog to actually work From: Ingo Molnar <[EMAIL PROTECTED]> this Xen related commit: commit 966812dc98e6a7fcdf759cbfa0efab77500a8868 Author: Jeremy Fitzhardinge <[EMAIL PROTECTED]> Date: Tue May 8 00:28:02 2007 -0700 Ignore stolen time in the softlockup watchdog broke the softlockup watchdog to never report any lockups. (!) print_timestamp defaults to 0, this makes the following condition always true: if (print_timestamp < (touch_timestamp + 1) || and we'll in essence never report soft lockups. apparently the functionality of the soft lockup watchdog was never actually tested with that patch applied ... [this is -stable material too.] Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> --- kernel/softlockup.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) Index: linux/kernel/softlockup.c =================================================================== --- linux.orig/kernel/softlockup.c +++ linux/kernel/softlockup.c @@ -79,10 +79,11 @@ void softlockup_tick(void) print_timestamp = per_cpu(print_timestamp, this_cpu); /* report at most once a second */ - if (print_timestamp < (touch_timestamp + 1) || - did_panic || - !per_cpu(watchdog_task, this_cpu)) + if ((print_timestamp >= touch_timestamp && + print_timestamp < (touch_timestamp + 1)) || + did_panic || !per_cpu(watchdog_task, this_cpu)) { return; + } /* do not print during early bootup: */ if (unlikely(system_state != SYSTEM_RUNNING)) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/