Messages in this thread | | | Date | Thu, 24 Feb 2011 12:10:45 +1030 | From | Arthur Marsh <> | Subject | Re: [Alsa-user] new source of MIDI playback slow-down identified - 5a03b051ed87e72b959f32a86054e1142ac4cf55 thp: use compaction in kswapd for GFP_ATOMIC order > 0 |
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Andrea Arcangeli wrote, on 24/02/11 10:29: > On Thu, Feb 24, 2011 at 08:25:43AM +1030, Arthur Marsh wrote: >> One more combination I tried: >> >> Mel Gorman's mm/compaction.c patch with Andrea Archangeli's >> kswapd-high_wmark + compaction-no-kswapd-3 patches - kswapd0 CPU less >> than 2 percent and no noticable slowdown of MIDI playback. > > Applying Mel's patch on top should decrease latency more. > >> If you can send me an updated patch compaction-no-kswapd-3 (I presume >> that kswapd-high_wmark is still needed) it would be easier for me to apply. > > It's a compaction-kswapd-3. It's likely going to work the same as the > previous compaction-kswapd-2 (not as good as > compaction-no-kswapd). It's better to apply both the kswapd-high_wmark > and Mel's patch too (not only this one) during testing.
OK, with kswapd-high_wmark + compaction-kswapd-3 + Mel's patch (with the compaction initialisation fix), MIDI playback is fine. kswapd0 CPU can very occasionally hit equal highest (17 percent was the highest I noticed, but is generally below the top 4-5 processes and less than 10 percent when working, dropping to around 0.3 percent when swap activity has subsided). This was with loading KDE 3.5.10, konversation, aptitude -u, icedove and iceweasel with several dozen tabs in addition to aplaymidi.
Regards,
Arthur.
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