From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx107.postini.com [74.125.245.107]) by kanga.kvack.org (Postfix) with SMTP id 4D1BD6B0126 for ; Fri, 17 Feb 2012 15:20:11 -0500 (EST) Received: by bkty12 with SMTP id y12so4406590bkt.14 for ; Fri, 17 Feb 2012 12:20:09 -0800 (PST) Message-ID: <4F3EB675.9030702@openvz.org> Date: Sat, 18 Feb 2012 00:20:05 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: Fine granularity page reclaim References: <20120217092205.GA9462@gmail.com> In-Reply-To: <20120217092205.GA9462@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Zheng Liu Cc: "linux-mm@kvack.org" Zheng Liu wrote: > Hi all, > > Currently, we encounter a problem about page reclaim. In our product system, > there is a lot of applictions that manipulate a number of files. In these > files, they can be divided into two categories. One is index file, another is > block file. The number of index files is about 15,000, and the number of > block files is about 23,000 in a 2TB disk. The application accesses index > file using mmap(2), and read/write block file using pread(2)/pwrite(2). We hope > to hold index file in memory as much as possible, and it works well in Redhat > 2.6.18-164. It is about 60-70% of index files that can be hold in memory. > However, it doesn't work well in Redhat 2.6.32-133. I know in 2.6.18 that the > linux uses an active list and an inactive list to handle page reclaim, and in > 2.6.32 that they are divided into anonymous list and file list. So I am > curious about why most of index files can be hold in 2.6.18? The index file > should be replaced because mmap doesn't impact the lru list. There was my patch for fixing similar problem with shared/executable mapped pages "vmscan: promote shared file mapped pages" commit 34dbc67a644f and commit c909e99364c maybe it will help in your case. > > BTW, I have some problems that need to be discussed. > > 1. I want to let index and block files are separately reclaimed. Is there any > ways to satisify me in current upstream? > > 2. Maybe we can provide a mechansim to let different files to be mapped into > differnet nodes. we can provide a ioctl(2) to tell kernel that this file should > be mapped into a specific node id. A nid member is added into addpress_space > struct. When alloc_page is called, the page can be allocated from that specific > node id. > > 3. Currently the page can be reclaimed according to pid in memcg. But it is too > coarse. I don't know whether memcg could provide a fine granularity page > reclaim mechansim. For example, the page is reclaimed according to inode number. > > I don't subscribe this mailing list, So please Cc me. Thank you. > > Regards, > Zheng > > -- > 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 -- 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