Andrew Morton wrote: > On Tue, 27 Mar 2007 14:49:20 -0700 Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote: > > >> The softlockup watchdog is currently a nuisance in a virtual machine, >> since the whole system could have the CPU stolen from it for a long >> period of time. While it would be unlikely for a guest domain to be >> denied timer interrupts for over 10s, it could happen and any softlockup >> message would be completely spurious. >> >> Earlier I proposed that sched_clock() return time in unstolen >> nanoseconds, which is how Xen and VMI currently implement it. If the >> softlockup watchdog uses sched_clock() to measure time, it would >> automatically ignore stolen time, and therefore only report when the >> guest itself locked up. When running native, sched_clock() returns >> real-time nanoseconds, so the behaviour would be unchanged. >> >> Note that sched_clock() used this way is inherently per-cpu, so this >> patch makes sure that the per-processor watchdog thread initialized >> its own timestamp. >> > > This patch > (ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc6/2.6.21-rc6-mm1/broken-out/ignore-stolen-time-in-the-softlockup-watchdog.patch) > causes six failures in the locking self-tests, which I must say is rather > clever of it. > Interesting. Which variation of sched_clock do you have in your tree at the moment? J _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
