From: zhangkui <zhangkui@xxxxxxxx> Subject: mm/madvise: add MADV_WILLNEED to process_madvise() 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, System Management Software can read-ahead memory of the process immediately when the app switches to forground. Calling process_madvise() with MADV_WILLNEED can meet this need. Link: https://lkml.kernel.org/r/20210804082010.12482-1-zhangkui@xxxxxxxx Signed-off-by: zhangkui <zhangkui@xxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/madvise.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/madvise.c~mm-madvise-add-madv_willneed-to-process_madvise +++ a/mm/madvise.c @@ -1048,6 +1048,7 @@ process_madvise_behavior_valid(int behav switch (behavior) { case MADV_COLD: case MADV_PAGEOUT: + case MADV_WILLNEED: return true; default: return false; _
