[CC Andrew] On Sun 04-06-17 13:01:09, Yu Zhao wrote: > Saw need_resched() warnings when swapping on large swapfile (TBs) > because continuously allocating many pages in swap_cgroup_prepare() > took too long. > > We already cond_resched when freeing page in swap_cgroup_swapoff(). > Do the same for the page allocation. > > Signed-off-by: Yu Zhao <[email protected]> > Acked-by: Michal Hocko <[email protected]> > Acked-by: Vladimir Davydov <[email protected]> > --- > Changelog since v1: > * clarify the problem in the commit message > > mm/swap_cgroup.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c > index ac6318a064d3..3405b4ee1757 100644 > --- a/mm/swap_cgroup.c > +++ b/mm/swap_cgroup.c > @@ -48,6 +48,9 @@ static int swap_cgroup_prepare(int type) > if (!page) > goto not_enough_page; > ctrl->map[idx] = page; > + > + if (!(idx % SWAP_CLUSTER_MAX)) > + cond_resched(); > } > return 0; > not_enough_page: > -- > 2.13.0.506.g27d5fe0cd-goog
-- Michal Hocko SUSE Labs
