Messages in this thread | | | From | Con Kolivas <> | Subject | Re: [PATCH] mm: swap prefetch improvements | Date | Tue, 22 May 2007 20:37:54 +1000 |
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On Tuesday 22 May 2007 20:25, Ingo Molnar wrote: > * Con Kolivas <kernel@kolivas.org> wrote: > > > > there was nothing else running on the system - so i suspect the > > > > swapin activity flagged 'itself' as some 'other' activity and > > > > stopped? The swapins happened in 4 bursts, separated by 5 seconds > > > > total idleness. > > > > > > I've noted burst swapins separated by some seconds of pause in my > > > desktop system too (with sp_tester and an idle gnome). > > > > That really is expected, as just about anything, including journal > > writeout, would be enough to put it back to sleep for 5 more seconds. > > note that nothing like that happened on my system - in the > swap-prefetch-off case there was _zero_ IO activity during the sleep > period.
Ok, granted it's _very_ conservative. I really don't want to risk its presence being a burden on anything, and the iowait it induces probably makes it turn itself off for another PREFETCH_DELAY (5s). I really don't want to cross the line to where it is detrimental in any way. Not dropping out on a cond_resched and perhaps making the delay tunable should be enough to make it a little less "sleepy".
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