From 8b1b654141f317403b723bebf2fb68af4c54cc37 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 6 Aug 2020 23:22:12 -0700 Subject: [PATCH] mm: memcontrol: restore proper dirty throttling when memory.high changes Commit 86e304a2ec41 ("mm: memcontrol: try harder to set a new memory.high") inadvertently removed a callback to recalculate the writeback cache size in light of a newly configured memory.high limit. Without letting the writeback cache know about a potentially heavily reduced limit, it may permit too many dirty pages, which can cause unnecessary reclaim latencies or even avoidable OOM situations. This was spotted while reading the code, it hasn't knowingly caused any problems in practice so far. Fixes: 86e304a2ec41 ("mm: memcontrol: try harder to set a new memory.high") Signed-off-by: Johannes Weiner Signed-off-by: Andrew Morton Reviewed-by: Shakeel Butt Acked-by: Chris Down Acked-by: Michal Hocko Cc: Roman Gushchin Link: http://lkml.kernel.org/r/20200728135210.379885-1-hannes@cmpxchg.org Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 369d9e1d83330..856db3ba30938 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6273,6 +6273,8 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, page_counter_set_high(&memcg->memory, high); + memcg_wb_domain_size_changed(memcg); + return nbytes; } -- 2.39.5