From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id E5F7E6B01F1 for ; Mon, 5 Apr 2010 21:25:39 -0400 (EDT) Date: Tue, 6 Apr 2010 09:25:36 +0800 From: Shaohua Li Subject: Re: [PATCH]vmscan: handle underflow for get_scan_ratio Message-ID: <20100406012536.GB18672@sli10-desk.sh.intel.com> References: <20100402181307.6470.A69D9226@jp.fujitsu.com> <20100402092441.GA21100@sli10-desk.sh.intel.com> <20100404231558.7E00.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100404231558.7E00.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "Wu, Fengguang" List-ID: On Sun, Apr 04, 2010 at 10:19:06PM +0800, KOSAKI Motohiro wrote: > > On Fri, Apr 02, 2010 at 05:14:38PM +0800, KOSAKI Motohiro wrote: > > > > > > This patch makes a lot of sense than previous. however I think <1% anon ratio > > > > > > shouldn't happen anyway because file lru doesn't have reclaimable pages. > > > > > > <1% seems no good reclaim rate. > > > > > > > > > > Oops, the above mention is wrong. sorry. only 1 page is still too big. > > > > > because under streaming io workload, the number of scanning anon pages should > > > > > be zero. this is very strong requirement. if not, backup operation will makes > > > > > a lot of swapping out. > > > > Sounds there is no big impact for the workload which you mentioned with the patch. > > > > please see below descriptions. > > > > I updated the description of the patch as fengguang suggested. > > > > > > Umm.. sorry, no. > > > > > > "one fix but introduce another one bug" is not good deal. instead, > > > I'll revert the guilty commit at first as akpm mentioned. > > Even we revert the commit, the patch still has its benefit, as it increases > > calculation precision, right? > > no, you shouldn't ignore the regression case. I don't think this is serious. In my calculation, there is only 1 page swapped out for 6G anonmous memory. 1 page should haven't any performance impact. Thanks, Shaohua -- 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