Messages in this thread | | | Date | Mon, 19 Apr 2004 21:53:31 +1000 | From | Nick Piggin <> | Subject | Re: CFQ iosched praise: good perfomance and better latency |
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Pedro Larroy wrote: > On Mon, Apr 19, 2004 at 04:12:56PM +1000, Nick Piggin wrote:
>>Well I think Pedro actually means *seconds*, not ms. The URL >>shows AS peaks at nearly 10 seconds latency, and CFQ over 2s. > > > Yes, I meant seconds, my mistake. I will be testing elevator=noop this > evening. >
That would be interesting.
> >>It really seems like a raid problem though, because latency >>measured at the individual devices is under 250ms for AS. > > > Probably. But I was surprised to find that bonnie gave similar results > with CFQ and with AS when benchmarking the swraid5.
I haven't used bonnie, but I think it is single threaded, isn't it? If that is the case, then the IO scheduler will make little or no difference, so your result is not surprising. - 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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