From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <485F2CA2.8060106@ah.jp.nec.com> Date: Mon, 23 Jun 2008 13:54:58 +0900 From: Takenori Nagano MIME-Version: 1.0 Subject: Re: [patch] memory reclaim more efficiently References: <485EF481.30409@ah.jp.nec.com> <20080623102854.37BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> In-Reply-To: <20080623102854.37BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KOSAKI Motohiro Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Keiichi KII List-ID: KOSAKI Motohiro wrote: > > Hi nagano-san, > > >> >> In shrink_zone(), system can not return to user mode before it finishes to >> >> search LRU list. IMHO, it is very wasteful, since the user processes stay >> >> unnecessarily long time in shrink_zone() loop and application response time >> >> becomes relatively bad. This patch changes shrink_zone() that it finishes memory >> >> reclaim when it reclaims enough memory. >> >> >> >> the conditions to end searching: >> >> >> >> 1. order of request page is 0 >> >> 2. process is not kswapd. >> >> 3. satisfy the condition to return try_to_free_pages() >> >> # nr_reclaim > SWAP_CLUSTER_MAX Hi Kosaki-san, > > I have 3 question. > > > > 1. Do you have any performance number? I tested some, but I don't collect data. :-( I will test again and post results. > > 2. I think this patch advocate many try_to_free_pages() called is better than > > one try_to_free_page waste long time. right? > > and, why do you think so? I think user process is stopped long time on memory reclaim is not good. It is enough for user process to reclaim memory is needed. We have kswapd memory reclaim daemon. I think memory reclaim is kswapd's job. > > 3. if this patch improve perfomance, I guess DEF_PRIORITY is > > too small on your machine. > > if DEF_PRIORITY is proportional to system memory, do your problem are solved? Your idea is so nice. :-) IMHO, it is not perfect if reclaimable memory is not on front. Thanks, Takenori -- 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