From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 6AE156B004A for ; Tue, 13 Mar 2012 04:36:29 -0400 (EDT) Received: by ggeq1 with SMTP id q1so332800gge.14 for ; Tue, 13 Mar 2012 01:36:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20120313082818.GA5421@gmail.com> References: <20120313024818.GA7125@barrios> <1331620214-4893-1-git-send-email-wenqing.lz@taobao.com> <20120313064832.GA4968@gmail.com> <4F5EF563.5000700@openvz.org> <20120313080535.GA5243@gmail.com> <20120313082818.GA5421@gmail.com> Date: Tue, 13 Mar 2012 14:06:28 +0530 Message-ID: Subject: Re: Fwd: Control page reclaim granularity From: Kautuk Consul Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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, linux-kernel@vger.kernel.org > > Yes, I think so. =A0But it seems that there has some codes that are > possible to be abused. =A0For example, as I said previously, applications > can mmap a normal data file with PROT_EXEC flag. =A0Then this file gets a > high priority to keep in memory (commit: 8cab4754). =A0So my point is tha= t > we cannot control applications how to use these mechanisms. =A0We just > provide them and let applications to choose how to use them. > :-) > That's true, but we are not talking about higher priority here, because in extreme memory reclaim case even PROT_EXEC pages will be reclaimed. But I understand your point. It might be okay to have this for all privileges applications. The only problem that might happen might be in OOM because we will have to include selection points for these page-cache pages (proportionately) while finding the most expensive process to kill. ( I'm talking about the page-cache pages which are not mapped to usermode page-tables at all. ) If any usermode application reads in an extremely huge file, whose inode has been set to AS_UNEVICTABLE, we might want to kill those applications that read in those pages(proportionately) so that the guilty application can be killed. -- 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