Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754160Ab2K3DkD (ORCPT ); Thu, 29 Nov 2012 22:40:03 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:60187 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753986Ab2K3Dj7 convert rfc822-to-8bit (ORCPT ); Thu, 29 Nov 2012 22:39:59 -0500 X-IronPort-AV: E=Sophos;i="4.83,346,1352044800"; d="scan'208";a="6303939" Message-ID: <50B82A7C.8020202@cn.fujitsu.com> Date: Fri, 30 Nov 2012 11:39:40 +0800 From: Lin Feng User-Agent: Mozilla/5.0 (X11; Linux i686; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Zach Brown CC: Andrew Morton , viro@zeniv.linux.org.uk, bcrl@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, mhocko@suse.cz, hughd@google.com, cl@linux.com, mgorman@suse.de, minchan@kernel.org, isimatu.yasuaki@jp.fujitsu.com, laijs@cn.fujitsu.com, wency@cn.fujitsu.com, tangchen@cn.fujitsu.com, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [BUG REPORT] [mm-hotplug, aio] aio ring_pages can't be offlined References: <1354172098-5691-1-git-send-email-linfeng@cn.fujitsu.com> <20121129153930.477e9709.akpm@linux-foundation.org> <20121130000443.GK18574@lenny.home.zabbo.net> In-Reply-To: <20121130000443.GK18574@lenny.home.zabbo.net> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/30 11:39:26, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/30 11:39:27 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1290 Lines: 38 Hi Zach, Thanks for your advice. So agree, I will look into it to lead aio to use non-movable pages. Thanks, linfeng On 11/30/2012 08:04 AM, Zach Brown wrote: >> The best I can think of is to make changes in or around >> get_user_pages(), to steal the pages from userspace and replace them >> with non-movable ones before pinning them. The performance cost of >> something like this would surely be unacceptable for direct-io, but >> maybe OK for the aio ring and futexes. > > In the aio case it seems like it could be taught to populate the mapping > with non-movable pages to begin with. It's calling get_user_pages() a > few lines after instantiating the mapping itself with do_mmap_pgoff(). > > - z > -- -------------------------------------------------- Lin Feng Development Dept.I Nanjing Fujitsu Nanda Software Tech. Co., Ltd.(FNST) No. 6 Wenzhu Road, Nanjing, 210012, China PHONE：+86-25-86630566-8557 COINS：7998-8557 FAX：+86-25-83317685 MAIL：linfeng@cn.fujitsu.com -------------------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/