Messages in this thread | | | Date | Sat, 21 Aug 2004 11:10:36 +0200 | From | Ingo Molnar <> | Subject | Re: [patch] voluntary-preempt-2.6.8.1-P6 |
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* Lee Revell <rlrevell@joe-job.com> wrote:
> Also I have noticed a pattern with the XFree86 schedule() latencies, > they all have a section like this: > > 04000002 0.003ms (+0.000ms): effective_prio (recalc_task_prio) > 04000002 0.003ms (+0.000ms): enqueue_task (schedule) > 00000002 0.006ms (+0.003ms): __switch_to (schedule) > 00000002 0.088ms (+0.082ms): finish_task_switch (schedule) > 00010002 0.090ms (+0.001ms): do_IRQ (finish_task_switch)
> I presume the 04000002 -> 00000002 is some interrupt being unmasked > (or interrupts being globally enabled), then there's a 60-80 usec > latency in schedule().
0x04000000 is PREEMPT_ACTIVE - which is just a bit we set to make sure we dont try to preempt recursively.
but the XFree86 latency is interesting indeed. It could be the effect of the now-enlarged ioperm() bitmap! 80 usecs is excessive.
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