Messages in this thread | | | From | <> | Subject | RE: [PATCH] vmevent: Use 'struct vmevent_attr' for vmevent_fd() ABI | Date | Wed, 7 Mar 2012 07:53:37 +0000 |
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> -----Original Message----- > From: ext Anton Vorontsov [mailto:anton.vorontsov@linaro.org] > Sent: 07 March, 2012 01:00 > To: Pekka Enberg > Cc: linux-kernel@vger.kernel.org; Moiseichuk Leonid (Nokia-MP/Espoo); ... > Sorry for hijacking this thread, but speaking of big changes. Are there any > plans or ideas to add other methods of sampling, i.e. something not timer- > based? ... > Though, current vmevent seems not so lightweigh in sense of battery usage > and accuracy (i.e. how quick we're able to detect the crossed threshold). To > get better accuracy we would need to run timer at higher frequencies, but > then we would waste more battery.
One of patch I sent was about switching to deferred timer. This API should not be 100% accurate first, and using deferred timers will allow to sleep properly when system has no activity. I hope Pekka will accept the next patch as well.
> > Sure, vmevent is still lightweight in sense that it does not cause much > runtime overhead or memory wastage (unlike cgroups).
"Timer work" is really lightweight.
> > The only idea I have for vmevent is to make some hybrid: timer plus shrinker > API. That way we would detect "low memory" events fast enough via > shrinker API, and thus run timer at low freq.
I used the same, see post about memnotify. Shrinker roll timer to be triggered soon.
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