From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 83DA16B0071 for ; Tue, 23 Nov 2010 19:13:56 -0500 (EST) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id oAO0DsSA017983 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 24 Nov 2010 09:13:54 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id D37B445DE5C for ; Wed, 24 Nov 2010 09:13:53 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 84E6645DE56 for ; Wed, 24 Nov 2010 09:13:53 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 4FD2DE08001 for ; Wed, 24 Nov 2010 09:13:53 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id CE4811DB805F for ; Wed, 24 Nov 2010 09:13:52 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [RFC 1/2] deactive invalidated pages In-Reply-To: <87hbf89jfk.fsf@gmail.com> References: <20101122143817.E242.A69D9226@jp.fujitsu.com> <87hbf89jfk.fsf@gmail.com> Message-Id: <20101124091249.7BEB.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 24 Nov 2010 09:13:51 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Ben Gamari Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , Andrew Morton , linux-mm , LKML , Peter Zijlstra , Rik van Riel , Johannes Weiner , Nick Piggin List-ID: > On Tue, 23 Nov 2010 16:16:55 +0900 (JST), KOSAKI Motohiro wrote: > > > By Other approach, app developer uses POSIX_FADV_DONTNEED. > > > But it has a problem. If kernel meets page is writing > > > during invalidate_mapping_pages, it can't work. > > > It is very hard for application programmer to use it. > > > Because they always have to sync data before calling > > > fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could > > > be discardable. At last, they can't use deferred write of kernel > > > so that they could see performance loss. > > > (http://insights.oetiker.ch/linux/fadvise.html) > > > > If rsync use the above url patch, we don't need your patch. > > fdatasync() + POSIX_FADV_DONTNEED should work fine. > > > This is quite true, but the patch itself is fairly invasive and > unnecessarily so which makes it unsuitable for merging in the eyes of > the rsync maintainers (not that I can blame them). This is by no fault > of its author; using fadvise is just far harder than it should be. Yeah. I agree with this patch don't have negative impact. I was only curious why Minchan drop autodetect logic. Please don't think I'm against your effort. 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org