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 9A2426B004D for ; Tue, 19 May 2009 00:43:42 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n4J4iLTm003010 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 19 May 2009 13:44:21 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 67F4745DE53 for ; Tue, 19 May 2009 13:44:21 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 4A35045DE51 for ; Tue, 19 May 2009 13:44:21 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 435EA1DB803F for ; Tue, 19 May 2009 13:44:21 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id E11D41DB803A for ; Tue, 19 May 2009 13:44:20 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 2/3] vmscan: make mapped executable pages the first class citizen In-Reply-To: <20090519133422.4ECC.A69D9226@jp.fujitsu.com> References: <20090519032759.GA7608@localhost> <20090519133422.4ECC.A69D9226@jp.fujitsu.com> Message-Id: <20090519134253.4ECF.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 19 May 2009 13:44:19 +0900 (JST) Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Wu Fengguang , Christoph Lameter , Andrew Morton , LKML , Elladan , Nick Piggin , Johannes Weiner , Peter Zijlstra , Rik van Riel , "tytso@mit.edu" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" List-ID: > > begin: 2479 2344 9659 210 0 579643 > > end: 284 232010 234142 260 772776 20917184 > > restore: 379 232159 234371 301 774888 20967849 > > > > The numbers show that > > > > - The startup pgmajfault of 2.6.30-rc4-mm is merely 1/3 that of 2.6.29. > > I'd attribute that improvement to the mmap readahead improvements :-) > > > > - The pgmajfault increment during the file copy is 633-630=3 vs 260-210=50. > > That's a huge improvement - which means with the VM_EXEC protection logic, > > active mmap pages is pretty safe even under partially cache hot streaming IO. > > > > - when active:inactive file lru size reaches 1:1, their scan rates is 1:20.8 > > under 10% cache hot IO. (computed with formula Dpgdeactivate:Dpgfree) > > That roughly means the active mmap pages get 20.8 more chances to get > > re-referenced to stay in memory. > > > > - The absolute nr_mapped drops considerably to 1/9 during the big IO, and the > > dropped pages are mostly inactive ones. The patch has almost no impact in > > this aspect, that means it won't unnecessarily increase memory pressure. > > (In contrast, your 20% mmap protection ratio will keep them all, and > > therefore eliminate the extra 41 major faults to restore working set > > of zsh etc.) > > I'm surprised this. > Why your patch don't protect mapped page from streaming io? I guess you use initlevel=5 and use only terminal, right? if so, dropping some graphics component makes sense. > > I strongly hope reproduce myself, please teach me reproduce way. -- 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