From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 21FBD6B01F0 for ; Mon, 30 Aug 2010 23:46:55 -0400 (EDT) Received: by iwn33 with SMTP id 33so7571776iwn.14 for ; Mon, 30 Aug 2010 20:46:53 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4C7C6959.3030801@redhat.com> References: <20100831095140.87C7.A69D9226@jp.fujitsu.com> <4C7C6959.3030801@redhat.com> Date: Tue, 31 Aug 2010 12:46:53 +0900 Message-ID: Subject: Re: [PATCH] vmscan: prevent background aging of anon page in no swap system From: Minchan Kim Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: KOSAKI Motohiro , Ying Han , Andrew Morton , linux-mm , LKML , Venkatesh Pallipadi , Johannes Weiner List-ID: On Tue, Aug 31, 2010 at 11:30 AM, Rik van Riel wrote: > On 08/30/2010 09:23 PM, Minchan Kim wrote: > >> Ying's one and mine both has a same effect. >> Only difference happens swap is full. My version maintains old >> behavior but Ying's one changes the behavior. I admit swap full is >> rare event but I hoped not changed old behavior if we doesn't find any >> problem. >> If kswapd does aging when swap full happens, is it a problem? > > It may be a good thing, since swap will often be freed again > (when something is swapped in, or exits). > > Having some more anonymous pages sit on the inactive list > gives them a chance to get used again, potentially giving > us a better chance of preserving the working set when swap > is full or near full a lot of the time. Do you mean we would be better to do background aging when swap is full? I wanted it. So I used total_swap_pages to protect working set when swap is full. But Ying and KOSAKI's don't like it since it makes code inconsistent or not simply. And I agree it's rare event as KOSAKI mentioned. Hmm... What do you think about it? If you don't mind, I will resend latest version(use nr_swap_page usage and compile out inactive_anon_is_low in case of !CONFIG_SWAP). -- Kind regards, Minchan Kim -- 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