Messages in this thread | | | Date | Wed, 27 Oct 2004 07:19:10 -0500 | From | "K.R. Foley" <> | Subject | Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0 |
| |
Ingo Molnar wrote: > * Ingo Molnar <mingo@elte.hu> wrote: > > >>>Still problems with interactive behavior. Running KDE, with top >>>running in xterm, scrolling through the menus I get some pauses. When >>>the pauses occur I see kdeinit hit the top of the list and sometimes >>>consuming 90% or more of a CPU and idle usage drops to 30-40%. I do >>>see some latency traces (not really high ones) in the log that were >>>generated by kdeinit but I think they were generated prior to when >>>these pauses occurred, most likely when logging in. >> >>is this 90% or more CPU time system (kernel) overhead or userspace >>overhead? >
It appears that most of the time is being consumed in system (~50% vs. ~6%). > > another thing to watch for is the context-switch rate in vmstat. -V0.3 > patches include a hack that include involuntary context-switches (mutex > context switches) in the context-switch stat as well. (previously those > were reported in a separate field which vmstat didnt pick up.) > > So if the context-switch rate shots up to above say 100K/sec that is a > sure sign of some mutex badness. The livelock scenarios i solved in > -V0.3 occasionally generated a more than 500K/sec context-switch rate on > a 2GHz box. Having just a couple of thousand per sec isnt by itself a > sign of anything unusual.
As for the context-switch, I do see this jump up to ~10-11K/sec from ~4-5K/sec and I see this only when I trigger the pauses.
> > Ingo >
kr - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |