From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: [PATCH] mm: memcontrol: restore proper dirty throttling when memory.high changes Date: Tue, 28 Jul 2020 09:52:09 -0400 Message-ID: <20200728135210.379885-1-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=EtW0ADoRwQtOsaGG7oJlooe3S87y53RN1USDHS3OX1k=; b=n1QWWvhgXYfYFQhyOqcZpff1NCZlRpZRU+M57YX8VkjXTtd3GqfnDkYU0Ml146ZUTZ EMUF3jGXqq0ZC+jlxfvAVMjoHJNWyaygZPYp4hXRevNGlGHVvpyCD8PlVbquWCb5nH4w UzI+8KI2BOpWhsINM70UMwN4agULCxVCtHtZj8ZAUgZk2Mz6MbJ3wids2nV60eUD5OT2 G5sgsBxiIAMoMM42EOEJipYA/duIJUeWlfrsrEeW+/D40GXy1ycVavy2AIRGeLsLtIh6 AUs2Y7iVWX1FTqBsZUxSi2UE2j1cv4OU9emJT+b4CA49q6ooCVZ3b/20TcvF6D0xPnw0 Q+mw== Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: Michal Hocko , Roman Gushchin , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org Commit 8c8c383c04f6 ("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: 8c8c383c04f6 ("mm: memcontrol: try harder to set a new memory.high") Signed-off-by: Johannes Weiner --- mm/memcontrol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13f559af1ab6..805a44bf948c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6071,6 +6071,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, break; } + memcg_wb_domain_size_changed(memcg); return nbytes; } -- 2.27.0