From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <50B82A7C.8020202@cn.fujitsu.com> Date: Fri, 30 Nov 2012 11:39:40 +0800 From: Lin Feng MIME-Version: 1.0 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> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: 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 Hi Zach, Thanks for your advice. So agree, I will look into it to lead aio=20 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=5Fuser=5Fpages(), 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. >=20 > 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=5Fuser=5Fpages() a > few lines after instantiating the mapping itself with do=5Fmmap=5Fpgoff(). >=20 > - z >=20 --=20 -------------------------------------------------- Lin Feng Development Dept.I Nanjing Fujitsu Nanda Software Tech. Co., Ltd.(FNST) No. 6 Wenzhu Road, Nanjing, 210012, China PHONE=EF=BC=9A+86-25-86630566-8557=20 COINS=EF=BC=9A7998-8557=20 FAX=EF=BC=9A+86-25-83317685 MAIL=EF=BC=9Alinfeng@cn.fujitsu.com -------------------------------------------------- = -- 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/ . Don't email: email@kvack.org