Messages in this thread Patch in this message | | | Date | Tue, 15 Jun 2004 06:56:16 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] Performance regression in 2.6.7-rc3 |
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* Con Kolivas <kernel@kolivas.org> wrote:
> with a little bit of detective work and help from Wli we tracked down that > this patch caused it: > [PATCH] sched: improve wakeup-affinity
> A massive increase in idle time was observed and the throughput > dropped by 40% Reversing this patch gave these results:
> backsched1: http://khack.osdl.org/stp/293865/ > Composite Query Processing Power Throughput Numerical Quantity > 193.93 145.95 257.67 > > It may be best to reverse this patch until the regression is better > understood.
agreed. It is weird because Nick said that pgsql was tested with the patch - and we applied the patch based on those good results. Nick?
Anyway, does the patch below fix the pgsql problem? It reverts to the more agressive idle-balancing variant (which isnt strictly necessary for the bw_pipe problem).
Ingo
Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- linux/kernel/sched.c +++ linux/kernel/sched.c @@ -1625,8 +1626,7 @@ return busiest; out_balanced: - if (busiest && idle != NOT_IDLE && max_load > SCHED_LOAD_SCALE) { + if (busiest && (idle == NEWLY_IDLE || + (idle == IDLE && max_load > SCHED_LOAD_SCALE)) ) { *imbalance = 1; return busiest; } - 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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