Re: [PATCH 1/2] mm/damon/sysfs: Implement recording feature

[SeongJae Park <sj@kernel.org>]

Hello Cuiyangpei,

On Fri, 1 Dec 2023 20:25:07 +0800 cuiyangpei <cuiyangpei@gmail.com> wrote:

> On Thu, Nov 30, 2023 at 07:44:20PM +0000, SeongJae Park wrote:
> > Hi Cuiyangpei,
> > 
> > On Thu, 30 Nov 2023 17:14:26 +0800 cuiyangpei <cuiyangpei@gmail.com> wrote:
> > 
> > > Hi SeongJae,
> > > 
> > > We also investigated the operation schemes you mentioned, but we don't
> > > think it can fit our needs.
> > > 
> > > On android, user will open many apps and switch between these apps as
> > > needs. We hope to monitor apps' memory access only when they are on
> > > foreground and record the memory access pattern when they are switched
> > > to the background. 
> > > 
> > > When avaliable memory reaches a threshold, we will use these access
> > > patterns with some strategies to recognize those memory that will have
> > > little impact on user experience and to reclaim them proactively.  
> > > 
> > > I'm not sure I have clarified it clearly, if you still have questions
> > > on this, please let us know.
> > 
> > So, to my understanding, you expect applications may keep similar access
> > pattern when they are in foreground, but have a different, less aggressive
> > access pattern in background, and therefore reclaim memory based on the
> > foreground-access pattern, right?
> >
> 
> Different apps may have different access pattern. On android, the apps will
> join in freeze cgroup and be frozen after switch to the background. So we 
> monitor apps' memory access only when they are in foreground.

FYI, I just posted an RFC patch that might help this use case.  Hopefully the
cover letter will explain why I think so.  If you need any clarifications or
have questions, please reply to the RFC patch series thread.

[1] https://lore.kernel.org/20260315210012.94846-1-sj@kernel.org


Thanks,
SJ

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