From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 632B68D0039 for ; Mon, 28 Feb 2011 01:00:37 -0500 (EST) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id A4D473EE0CB for ; Mon, 28 Feb 2011 15:00:33 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 8D9AA45DE55 for ; Mon, 28 Feb 2011 15:00:33 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 631E645DE56 for ; Mon, 28 Feb 2011 15:00:33 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 566F2E38002 for ; Mon, 28 Feb 2011 15:00:33 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0E578E08001 for ; Mon, 28 Feb 2011 15:00:33 +0900 (JST) Date: Mon, 28 Feb 2011 14:54:02 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration Message-Id: <20110228145402.65e6f200.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20110228054818.GF22700@random.random> References: <1298664299-10270-1-git-send-email-mel@csn.ul.ie> <1298664299-10270-3-git-send-email-mel@csn.ul.ie> <20110228111746.34f3f3e0.kamezawa.hiroyu@jp.fujitsu.com> <20110228054818.GF22700@random.random> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Mel Gorman , Andrew Morton , Arthur Marsh , Clemens Ladisch , Linux-MM , Linux Kernel Mailing List On Mon, 28 Feb 2011 06:48:18 +0100 Andrea Arcangeli wrote: > On Mon, Feb 28, 2011 at 11:17:46AM +0900, KAMEZAWA Hiroyuki wrote: > > BTW, I forget why we always take zone->lru_lock with IRQ disabled.... > > To decrease lock contention in SMP to deliver overall better > performance (not sure how much it helps though). It was supposed to be > hold for a very short time (PAGEVEC_SIZE) to avoid giving irq latency > problems. > memory hotplug uses MIGRATE_ISOLATED migrate types for scanning pfn range without lru_lock. I wonder whether we can make use of it (the function which memory hotplug may need rework for the compaction but migrate_type can be used, I think). Hmm. -Kame -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org