Messages in this thread | | | Date | Wed, 15 Sep 2004 08:55:10 +1000 | From | Nick Piggin <> | Subject | Re: [patch] sched: fix scheduling latencies for !PREEMPT kernels |
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Ingo Molnar wrote: > * Nick Piggin <nickpiggin@yahoo.com.au> wrote: > > >>Another thing, I don't mean this to sound like a rhetorical question, >>but if we have a preemptible kernel, why is it a good idea to sprinkle > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > >>cond_rescheds everywhere? Isn't this now the worst of both worlds? Why >>would someone who really cares about latency not enable preempt? > > > two things: > > 1) none of the big distros enables CONFIG_PREEMPT in their kernels - not > even SuSE. This is pretty telling. > > 2) 10 new cond_resched()'s are not precisely 'sprinkle everywhere'. >
No, but I mean putting them right down into fastpaths like the vmscan one, for example.
And if I remember correctly, you resorted to putting them into might_sleep as well (but I haven't read the code for a while, maybe you're now getting decent results without doing that). - 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/
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