Messages in this thread | | | Date | Thu, 7 Aug 2003 10:39:30 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH][2.6-mm] Readahead issues and AIO read speedup |
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Badari Pulavarty <pbadari@us.ibm.com> wrote: > > We should do readahead of actual pages required by the current > read would be correct solution. (like Suparna suggested).
I repeat: what will be the effect of this if all those pages are already in pagecache?
> When readahead window is closed, slow read code will be submitting IO in 4k > chunks. Infact, it will wait for the IO to finish, before reading next page. > Isn't it?
Yes.
> How would you ensure atleast 16k worth of pages are submitted > in a sinle chunk here ?
Need to work out why the window got itself shrunk, fix that, then constrain each readahead chunk to the size of the application's read() if the application just seeked, I think.
> I am hoping that forcing readhead code to read pages needed by current read > would address this problem.
You'll have Martin and Anton coming after you with SDET regressions.
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