Re: [PATCH v0 0/2] mm: swap: Gather swap entries and batch async release

[Chris Li <chrisl@kernel.org>]

On Tue, Sep 9, 2025 at 12:48 PM Suren Baghdasaryan <surenb@google.com> wrote:
> > > Exiting processes compete for CPU cycles, delaying the camera preview
> > > thread and causing visible stuttering - directly impacting user
> > > experience.
> >
> > Since the exit/kill is due to low memory situation, punting the memory
> > freeing to a low priority async mechanism will help in improving user
> > experience. Most probably the application (camera preview here) will get
> > into global reclaim and will compete for CPU with the async memory
> > freeing.
> >
> > What we really need is faster memory freeing and we should explore all
> > possible ways. As others suggested fix/improve the bottleneck in the
> > memory freeing path. In addition I think we should explore parallelizing
> > this as well.
> >
> > On Android, I suppose most of the memory is associated with single or
> > small set of processes and parallelizing memory freeing would be
> > challenging. BTW is LMKD using process_mrelease() to release the killed
> > process memory?
>
> Yes, LMKD has a reaper thread which wakes up and calls
> process_mrelease() after the main LMKD thread issued SIGKILL.

I feel this is a better solution to address the exit process that is too slow.

We are basically optimizing the exit() system call, I feel there
should be something we can do in the userspace before exit() to help
us without the kernel putting too much complexity into exit().
process_mrelease() souds fit the bill pretty well.

Chris