From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 8B1786B01E3 for ; Sun, 4 Apr 2010 10:19:12 -0400 (EDT) Date: Sun, 4 Apr 2010 23:19:06 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH]vmscan: handle underflow for get_scan_ratio In-Reply-To: <20100402092441.GA21100@sli10-desk.sh.intel.com> References: <20100402181307.6470.A69D9226@jp.fujitsu.com> <20100402092441.GA21100@sli10-desk.sh.intel.com> Message-Id: <20100404231558.7E00.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Shaohua Li Cc: kosaki.motohiro@jp.fujitsu.com, "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "Wu, Fengguang" List-ID: > 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. If we can remove the streaming io corner case by another patch, this patch can be considered to merge. thanks. -- 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