On Wed, 2009-10-07 at 20:34 +0200, Frans Pop wrote: > On Wednesday 07 October 2009, Frans Pop wrote: > > On Tuesday 06 October 2009, Frans Pop wrote: > > > I've checked for 2.6.31.1 now and iwlagn is listed high there too when > > > the system is idle, but with normal values of 60-100 ms. And phy0 has > > > normal values of below 10 ms. > > > I've now rebooted with today's mainline git; phy0 now frequently shows > > > with values of around 100 ms too (i.e. higher than last time). > > > > Mike privately sent me a script to try to capture the latencies with > > perf, but the perf output does not show any high latencies at all. It > > looks as if we may have found a bug in latencytop here instead. > > Not sure if it's relevant nor what it means, but I frequently see two lines > for iwlagn, e.g: > > Scheduler: waiting for cpu 102.4 msec 99.7 % > . 3.3 msec 0.3 % > > I get the same results with both latencytop 0.4 and 0.5. OK, I see latencytop spikes here on an idle box too, to the tune of up to a _second_. Booting with nohz=off seems to have cured it. I wanted to see if that's also the perf sched record -C N trouble I warned you not to try when recording with script, but unfortunately, after pulling this morning... marge:/root/tmp # perf sched lat --sort=max Segmentation fault ...perf sched got busted. Seems likely to be same thing for both though, as magnitude/frequency of bogons is very similar. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
