From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp01.in.ibm.com (8.13.1/8.13.1) with ESMTP id m1R4XUpR005021 for ; Wed, 27 Feb 2008 10:03:30 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1R4XUEh954544 for ; Wed, 27 Feb 2008 10:03:30 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.13.1/8.13.3) with ESMTP id m1R4XZ1N031772 for ; Wed, 27 Feb 2008 04:33:35 GMT Message-ID: <47C4E6CD.6090401@linux.vnet.ibm.com> Date: Wed, 27 Feb 2008 09:57:57 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [RFC][PATCH] page reclaim throttle take2 References: <20080226104647.FF26.KOSAKI.MOTOHIRO@jp.fujitsu.com> <1204060718.6242.333.camel@lappy> <20080227131939.4244.KOSAKI.MOTOHIRO@jp.fujitsu.com> In-Reply-To: <20080227131939.4244.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KOSAKI Motohiro Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, KAMEZAWA Hiroyuki , Rik van Riel , Lee Schermerhorn , Nick Piggin List-ID: KOSAKI Motohiro wrote: > Hi Peter, > >>> + >>> + atomic_t nr_reclaimers; >>> + wait_queue_head_t reclaim_throttle_waitq; >>> /* >>> * rarely used fields: >>> */ >> Small nit, that extra blank line seems at the wrong end of the text >> block :-) > > Agghhh, sorry ;-) > I'll fix at next post. > >>> +out: >>> + atomic_dec(&zone->nr_reclaimers); >>> + wake_up_all(&zone->reclaim_throttle_waitq); >>> + >>> + return ret; >>> +} >> Would it be possible - and worthwhile - to make this FIFO fair? > > Hmmm > may be, we don't need perfectly fair. > because try_to_free_page() is unfair mechanism. > > but I will test use wake_up() instead wake_up_all(). > it makes so so fair order if no performance regression happend. > > Thanks very useful comment. One more thing, I would request you to add default heuristics (number of reclaimers), based on the number of cpus in the system. Letting people tuning it is fine, but defaults should be related to number of cpus, nodes and zones on the system. Zones can be reaped in parallel per node and cpus allow threads to run in parallel. So please use that to come up with good defaults, instead of a number like "3". -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL -- 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