Re: [PATCH] mm/madvise: add MADV_WILLNEED to process_madvise()

From: Andrew Morton
Date: Wed Aug 04 2021 - 22:04:11 EST

On Wed, 4 Aug 2021 16:20:10 +0800 zhangkui <zhangkui@xxxxxxxx> wrote:

> There is a usecase in Android that an app process's memory is swapped out
> by process_madvise() with MADV_PAGEOUT, such as the memory is swapped to
> zram or a backing device. When the process is scheduled to running, like
> switch to foreground, multiple page faults may cause the app dropped
> frames.
> To reduce the problem, SMS can read-ahead memory of the process immediately
> when the app switches to forground.
> Calling process_madvise() with MADV_WILLNEED can meet this need.

This will require a small update to the process_madvise(2) manpage.
Can you please send a patch?