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 <yuzhao@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>