From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx170.postini.com [74.125.245.170]) by kanga.kvack.org (Postfix) with SMTP id ABF026B004D for ; Tue, 13 Mar 2012 03:47:42 -0400 (EDT) Received: by yenm8 with SMTP id m8so296710yen.14 for ; Tue, 13 Mar 2012 00:47:41 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20120313024818.GA7125@barrios> <1331620214-4893-1-git-send-email-wenqing.lz@taobao.com> <20120313064832.GA4968@gmail.com> <4F5EF563.5000700@openvz.org> Date: Tue, 13 Mar 2012 13:17:41 +0530 Message-ID: Subject: Re: Fwd: Control page reclaim granularity From: Kautuk Consul Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: minchan@kernel.org, riel@redhat.com, kosaki.motohiro@jp.fujitsu.com, Zheng Liu , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org On Tue, Mar 13, 2012 at 1:13 PM, Kautuk Consul wrote: > Hi, > > I noticed this discussion and decided to pitch in one small idea from my side. > > It would be nice to range lock an inode's pages by storing those > ranges which would be locked. > This could also add some good routines for the kernel in terms of > range locking for a single inode. > However, wouldn't this add some overhead to shrink_page_list() since > that code would need to go through > all these ranges while trying to reclaim a single page ? > > One small suggestion from my side is: > Why don't we implement something like : "Complete page-cache reclaim > control from usermode"? > In this, we can set/unset the mapping to AS_UNEVICTABLE (as Konstantin > mentioned) for a file's > inode from usermode by using ioctl or fcntl or maybe even go as far as > implementing an O_NORECL > option to the open system call. > Of course, only an application executing with root privileges should be allowed to set the inode's mapping flags in this manner. > After setting the AS_UNEVICTABLE, the usermode application can choose > to keep and remove pages by > using the fadvise(WILLNEED) and fadvise(DONTNEED). > > ( I think maybe the presence of any VMA is might not really be > required for this idea. ) > > Thanks, > Kautuk. -- 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