Messages in this thread |  | | Date | Tue, 8 May 2001 21:21:16 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] allocation looping + kswapd CPU cycles |
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On Tue, May 08 2001, Marcelo Tosatti wrote: > > The attached patch (against 2.4.5-pre1) fixes the looping symptom, by > > adding a counter and looping only twice for non-zero order allocations. > > Looks good. (actually Rik had a patch similar to this which fixed a real > case with cdda2wav just like you described)
Not cdda2wav, I pressume, but the optimization discussed here before that wasn't really doable because of the vm behaviour when doing
do try to alloc some amount of contiogous pages if (ok) break
lower number of pages wanted while true
CDROMREADAUDIO stopped doing this and fell back to single cdda frame size allocations because of these failures, even though it meant a huge decrease in speed. cdda2wav will ask for iirc 16 frames at the time, the current driver will try and to 8 first and then fall back to slower extraction if allocations fail.
-- Jens Axboe
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