From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] mm: vmscan: fix IO/refault regression in cache workingset transition Date: Tue, 4 Apr 2017 15:07:03 -0700 Message-ID: <20170404150703.742c49d73921df6369ed3dbd@linux-foundation.org> References: <20170404220052.27593-1-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170404220052.27593-1-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Johannes Weiner Cc: Rik van Riel , Mel Gorman , Michal Hocko , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com On Tue, 4 Apr 2017 18:00:52 -0400 Johannes Weiner wrote: > Since 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list") > we noticed bigger IO spikes during changes in cache access patterns. > > The patch in question shrunk the inactive list size to leave more room > for the current workingset in the presence of streaming IO. However, > workingset transitions that previously happened on the inactive list > are now pushed out of memory and incur more refaults to complete. > > This patch disables active list protection when refaults are being > observed. This accelerates workingset transitions, and allows more of > the new set to establish itself from memory, without eating into the > ability to protect the established workingset during stable periods. > > Fixes: 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list") > Signed-off-by: Johannes Weiner > Cc: # 4.7+ That's a pretty large patch and the problem has been there for a year. I'm not sure that it's 4.11 material, let alone -stable. Care to explain further? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org