Messages in this thread | | | Date | Tue, 9 Jul 2002 03:11:33 +0200 | From | "J.A. Magallon" <> | Subject | Re: pipe and af/unix latency differences between aa and jam on smp |
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On 2002.07.09 rwhron@earthlink.net wrote: >The -jam patchset is interesting because it starts out >with the entire -aa patchset and adds a few things. > >Sometimes small differences in LMbench between -jam and -aa are >just CPU bounces on SMP. The difference for pipe and af/unix latency >only appears on SMP too, but it is very consistent. (My k6/2 >has small differences between -aa and -jam for pipe and af/unix >latency). > >You will know better what could make the difference: > >This is the averages: > >*Local* Communication latencies in microseconds - smaller is better >------------------------------------------------------------------- >kernel Pipe AF/Unix >----------------- ------- ------- >2.4.19-pre10-aa4 33.941 70.216 >2.4.19-pre10-jam2 7.877 16.699 >
Candidates in pre10-jam2 could be:
11-irqbalance-B1.bz2 12-smptimers-A0.bz2 13-irqrate-A1.bz2
excluding anything that has nothing to do with pipes or latency.
Could you try latest -rc1-aa2 ? It includes also irqbalance, so it could be on varable less in the equation. I dropped smptimers and irqrate because they did not mix very well with bproc and O1 scheduler, but I can try to add them again.
I have a rc1-jam2 ready, but the only important change wrt SMP could be the mem-barrier specific implementation for P3/P4, and your box is an AMD.
??
-- J.A. Magallon \ Software is like sex: It's better when it's free mailto:jamagallon@able.es \ -- Linus Torvalds, FSF T-shirt Linux werewolf 2.4.19-rc1-jam2, Mandrake Linux 8.3 (Cooker) for i586 gcc (GCC) 3.1.1 (Mandrake Linux 8.3 3.1.1-0.7mdk) - 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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