Messages in this thread |  | | | From | Alexey Kopytov <> | | Subject | Re: Random file I/O regressions in 2.6 | | Date | Wed, 5 May 2004 03:01:31 +0400 |
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Ram Pai wrote: >Without the patch: >------------------ >Time spent for test: 20.6661s > >no of times window reset because of hits: 0 >no of times window reset because of misses: 7 >no of times window was shrunk because of hits: 6716 >no of times the page request was non-contiguous: 5880 >no of times the page request was contiguous : 19639 > >With the patch: >-------------- >Time spent for test: 19.5370s > >no of times window got reset because of hits: 0 >no of times window got reset because of misses: 0 >no of times window was shrunk because of hits: 5844 >no of times the page request was non-contiguous: 5830 >no of times the page request was contiguous : 20232 > >Would be nice if Alexey tries the patch on his machine and sees any >major difference.
Here's what I have (same hardware and test setups):
Without the patch (but with Ram's patch applied): ------------------ Time spent for test: 125.4429s no of times window reset because of hits: 0 no of times window reset because of misses: 127 no of times window was shrunk because of hits: 1153 no of times the page request was non-contiguous: 3968 no of times the page request was contiguous : 10686
With the patch: --------------- Time spent for test: 86.5459s no of times window reset because of hits: 0 no of times window reset because of misses: 0 no of times window was shrunk because of hits: 1066 no of times the page request was non-contiguous: 5860 no of times the page request was contiguous : 18099
I wonder if there are some plans to further improve 2.6 behavior on this workload to match that of 2.4? Is the remaing regression a result of the different readahead handling, or it might be caused by IDE driver or I/O scheduler tuning? -- Alexey Kopytov, Software Developer MySQL AB, www.mysql.com
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