Messages in this thread | | | Date | Thu, 24 Dec 2009 15:48:38 +0800 | From | Gui Jianfeng <> | Subject | Re: cfq-iosched: tiobench regression |
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Shaohua Li wrote: > We see about 30% regression in tiobench 32 threads 80M file sequential read. > The regression is caused by below commits. > > 5db5d64277bf390056b1a87d0bb288c8b8553f96 > The commit makes the slice too small. In the test, the slice is limitted > to 2 * idle_slice(300ms/32 < 2*idle_slice). This dramatically impacts io > thoughput. The low_latency knob used to be only impact random io, now it > impacts sequential io too. Any idea to fix it?
Hi Shaohua,
IMHO this shouldn't be a problem. Currently, low_latency is used to improve the latency for the whole system. If someone would like to achieve high throughput, just turn off low_latency knob.
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