From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gioh Kim Subject: Re: [PATCH 0/2] new APIs to allocate buffer-cache for superblock in non-movable area Date: Mon, 18 Aug 2014 13:44:38 +0900 Message-ID: <53F184B6.5080503@lge.com> References: <53EC4531.1000904@lge.com> <20140814142610.6f0d4194c373fef188870772@linux-foundation.org> <20140816185208.GA1589@quack.suse.cz> <53F153B4.1060309@lge.com> <20140818032422.GD23084@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE To: Theodore Ts'o , Jan Kara , Andrew Morton , Alexander Viro , "Paul E. McKenney" , Peter Zijlstra , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Dilger , linux-ext4@vger.kernel.org, Minchan Kim , Joonsoo Kim , =?UTF-8?B?7J206rG07Zi4?= Return-path: In-Reply-To: <20140818032422.GD23084@thunk.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 2014-08-18 =EC=98=A4=ED=9B=84 12:24, Theodore Ts'o =EC=93=B4 =EA=B8=80: > On Mon, Aug 18, 2014 at 10:15:32AM +0900, Gioh Kim wrote: >> >> My test platform has totally 1GB memory, 256MB for CMA and 768MB for= normal. >> I applied Joonsoo's patch: https://lkml.org/lkml/2014/5/28/64, so th= at >> 3/4 of allocation take place in normal area and 1/4 allocation take = place in CMA area. >> >> And my platform has 4 ext4 partitions. Each ext4 partition has 2 pag= e caches for superblock that >> are what this patch tries to move to out of CMA area. >> Therefore there are 8 page caches (8 pages size) that can prevent pa= ge migration. > > Yes, but are you actually *using* the ext4 partitions for anything? > If this is a realistic real world use case, file systems are used to > store, well, files, and that means there will be inodes and dentry > cache entries that will also be allocated. Does your test scenario > reflect real world usage? Yes. I'm working for LG Electronics. My test platform is currently selling item in the market. And also I test my patch when my platform is working as if real user us= es it. I think the page caches of the inodes and dentry are held for short tim= e. I can see pairs of get_bh and put_bh in inodes/dentry handling. I think inodes is allocated by kmem_cache_alloc in ext4_alloc_inode(). It is non-movable area allocation. > > Cheers, > > - Ted > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751349AbaHREon (ORCPT ); Mon, 18 Aug 2014 00:44:43 -0400 Received: from lgeamrelo01.lge.com ([156.147.1.125]:57894 "EHLO lgeamrelo01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750807AbaHREom (ORCPT ); Mon, 18 Aug 2014 00:44:42 -0400 X-Original-SENDERIP: 10.178.33.69 X-Original-MAILFROM: gioh.kim@lge.com Message-ID: <53F184B6.5080503@lge.com> Date: Mon, 18 Aug 2014 13:44:38 +0900 From: Gioh Kim User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: "Theodore Ts'o" , Jan Kara , Andrew Morton , Alexander Viro , "Paul E. McKenney" , Peter Zijlstra , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Dilger , linux-ext4@vger.kernel.org, Minchan Kim , Joonsoo Kim , =?UTF-8?B?7J206rG07Zi4?= Subject: Re: [PATCH 0/2] new APIs to allocate buffer-cache for superblock in non-movable area References: <53EC4531.1000904@lge.com> <20140814142610.6f0d4194c373fef188870772@linux-foundation.org> <20140816185208.GA1589@quack.suse.cz> <53F153B4.1060309@lge.com> <20140818032422.GD23084@thunk.org> In-Reply-To: <20140818032422.GD23084@thunk.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-08-18 오후 12:24, Theodore Ts'o 쓴 글: > On Mon, Aug 18, 2014 at 10:15:32AM +0900, Gioh Kim wrote: >> >> My test platform has totally 1GB memory, 256MB for CMA and 768MB for normal. >> I applied Joonsoo's patch: https://lkml.org/lkml/2014/5/28/64, so that >> 3/4 of allocation take place in normal area and 1/4 allocation take place in CMA area. >> >> And my platform has 4 ext4 partitions. Each ext4 partition has 2 page caches for superblock that >> are what this patch tries to move to out of CMA area. >> Therefore there are 8 page caches (8 pages size) that can prevent page migration. > > Yes, but are you actually *using* the ext4 partitions for anything? > If this is a realistic real world use case, file systems are used to > store, well, files, and that means there will be inodes and dentry > cache entries that will also be allocated. Does your test scenario > reflect real world usage? Yes. I'm working for LG Electronics. My test platform is currently selling item in the market. And also I test my patch when my platform is working as if real user uses it. I think the page caches of the inodes and dentry are held for short time. I can see pairs of get_bh and put_bh in inodes/dentry handling. I think inodes is allocated by kmem_cache_alloc in ext4_alloc_inode(). It is non-movable area allocation. > > Cheers, > > - Ted >