From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id D31616B0032 for ; Tue, 4 Jun 2013 11:24:39 -0400 (EDT) Message-ID: <51AE06B6.3030009@sr71.net> Date: Tue, 04 Jun 2013 08:24:38 -0700 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [v5][PATCH 6/6] mm: vmscan: drain batch list during long operations References: <20130603200202.7F5FDE07@viggo.jf.intel.com> <20130603200210.259954C3@viggo.jf.intel.com> <20130604060553.GF14719@blaptop> In-Reply-To: <20130604060553.GF14719@blaptop> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mgorman@suse.de, tim.c.chen@linux.intel.com On 06/03/2013 11:05 PM, Minchan Kim wrote: >> > This ensures that we drain the batch if we are about to perform a >> > pageout() or congestion_wait(), either of which will take some >> > time. We expect this to help mitigate the worst of the latency >> > increase that the batching could cause. > Nice idea but I could see drain before pageout but congestion_wait? That comment managed to bitrot a bit :( The first version of these had the drain before pageout() only. Then, Mel added a congestion_wait() call, and I modified the series to also drain there. But, some other patches took the congestion_wait() back out, so I took that drain back out. I _believe_ the only congestion_wait() left in there is a cgroup-related one that we didn't think would cause very much harm. -- 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