Messages in this thread | | | Date | Mon, 30 Jan 2012 13:45:12 +0800 | Subject | Re: Bad SSD performance with recent kernels | From | Shaohua Li <> |
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2012/1/30 Eric Dumazet <eric.dumazet@gmail.com>: > Le lundi 30 janvier 2012 à 11:17 +0800, Shaohua Li a écrit : > >> 1M block size is slow, I guess it's CPU related. >> >> And as for the big regression with newer kernel than 2.6.38, please >> check if idle=poll >> helps. CPU idle dramatically impacts disk performance and even latest >> cpuidle governor >> doesn't help for some CPUs. >> > > No change with idle=poll I mean the big regression might be related to CPU idle. because I saw really bad performance with CPU idle with some CPUs.
The 1M block size performance is lower than 128K is not. but I still guess it's CPU related (like copy). The test result is always like this IIRC. -- 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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