On Sat, Oct 10, 2009 at 01:22:16AM +0400, Michael Tokarev wrote: > Marcelo Tosatti wrote: > [snip] > >> Would be useful to collect sar (sar -B -b -u) output every one second >> in both host/guest. You already mentioned load was low, but this should >> give more details. > > Here we go: http://www.corpit.ru/mjt/hrtimer-interrupt-too-slow/ > > Two incindents - cases when hrtimer: interrupt is too slow were > reported in the guest (with Marcelo's patch so that min_delta is > increased to 50% only), happened at 11:44:48 and 21:46:56 (as > shown in guest-dmesg file). For both, there's `sar -BWbd' output > for a 2-minute interval (starting one minute before the delay > and ending one minute after) from both host and guest. > >> Was there swapping going on? > > Not as far as I can see, and sar output agrees. But I can read this from you guest traces: pgpgin/s pgpgout/s fault/s majflt/s pgfree/s pgscank/s pgscand/s pgsteal/s %vmeff 11:44:45 0.00 32.32 174.75 0.00 176.77 0.00 0.00 0.00 0.00 11:44:46 0.00 16.00 789.00 0.00 323.00 0.00 0.00 0.00 0.00 11:44:47 0.00 32.32 907.07 0.00 277.78 0.00 0.00 0.00 0.00 11:44:48 27.59 22.99 44.83 0.00 150.57 0.00 0.00 0.00 0.00 11:44:49 0.00 33.68 22.11 0.00 218.95 0.00 0.00 0.00 0.00 11:44:50 0.00 101.01 17.17 0.00 151.52 0.00 0.00 0.00 0.00 11:44:51 0.00 15.69 16.67 0.00 126.47 0.00 0.00 0.00 0.00 [...] 21:46:52 0.00 40.00 17.00 0.00 82.00 0.00 0.00 0.00 0.00 21:46:53 0.00 31.68 18.81 0.00 94.06 0.00 0.00 0.00 0.00 21:46:54 0.00 31.68 16.83 0.00 90.10 0.00 0.00 0.00 0.00 21:46:55 0.00 108.00 17.00 0.00 89.00 0.00 0.00 0.00 0.00 21:46:56 9.76 482.93 3890.24 0.00 439.02 0.00 0.00 0.00 0.00 21:46:57 0.00 760.00 8627.00 0.00 1133.00 0.00 0.00 0.00 0.00 21:46:58 0.00 84.85 2612.12 0.00 138.38 0.00 0.00 0.00 0.00 21:46:59 0.00 16.00 17.00 0.00 90.00 0.00 0.00 0.00 0.00 21:47:00 0.00 36.36 17.17 0.00 90.91 0.00 0.00 0.00 0.00 So it looks like there was some swapping in when the hrtimer (spuriously) hanged. Not sure how to correlate these results with the incident though... -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
