On Mon, 5 Oct 2009 16:13:31 +0200 Frans Pop <elendil@xxxxxxxxx> wrote: > On Monday 05 October 2009, Frans Pop wrote: > > With .32-rc3 I'm getting occasional skips from amarok while playing > > music from an NFS share (3 today so far), something I've not had in > > a long time. > > > > The reason looks to be that latencytop consistently shows 'iwlagn' > > as the top affected process with "Scheduler: waiting for CPU". > > Values of 100-140 ms occur frequently, but I've also seen higher > > values (180, 207). I don't remember seeing iwlagn high in the list > > before, but I have not checked earlier kernels yet. > > > > Added to that 'phy0' also frequently shows high with values of > > 25-75 ms. > > > > The system is otherwise essentially idle. Other processes typically > > show a latency < 5 ms. > > If I give the system some work to do (like compiling a kernel), the > latencies on iwlagn and phy0 disappear (values < 5 ms). > Is this related to ondemand frequency scaling? shouldn't be.... but can you do a 5 second or so timechart recording of this? That will capture all scheduler delays as well as the P states etc.... (to do a timechart recording, first make sure debugfs is mounted, and then do in tools/perf ./perf timechart record sleep 5 then you can turn it into an SVG with ./perf timechart ) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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
