On Thu, May 02, 2019 at 01:09:05PM -0700, Robert Kolchmeyer wrote: > From: Minchan Kim <minchan@xxxxxxxxxx> > > commit e496612c5130567fc9d5f1969ca4b86665aa3cbb upstream. > > Shakeel Butt reported he has observed in production systems that the job > loader gets stuck for 10s of seconds while doing a mount operation. It > turns out that it was stuck in register_shrinker() because some > unrelated job was under memory pressure and was spending time in > shrink_slab(). Machines have a lot of shrinkers registered and jobs > under memory pressure have to traverse all of those memcg-aware > shrinkers and affect unrelated jobs which want to register their own > shrinkers. > > To solve the issue, this patch simply bails out slab shrinking if it is > found that someone wants to register a shrinker in parallel. A downside > is it could cause unfair shrinking between shrinkers. However, it > should be rare and we can add compilcated logic if we find it's not > enough. > > [akpm@xxxxxxxxxxxxxxxxxxxx: tweak code comment] > Link: http://lkml.kernel.org/r/20171115005602.GB23810@bbox > Link: http://lkml.kernel.org/r/1511481899-20335-1-git-send-email-minchan@xxxxxxxxxx > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> > Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Reported-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Tested-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Acked-by: Michal Hocko <mhocko@xxxxxxxx> > Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > [rkolchmeyer: Backported to 4.14: adjusted context] > Signed-off-by: Robert Kolchmeyer <rkolchmeyer@xxxxxxxxxx> > --- > Backport of commit e496612c5130567fc9d5f1969ca4b86665aa3cbb upstream. > We would like to apply this to linux-4.14.y. > I needed to change the patch context for the patch to apply to linux-4.14.y. > The actual fix remains unchanged. Now queued up, thanks. greg k-h
