From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx189.postini.com [74.125.245.189]) by kanga.kvack.org (Postfix) with SMTP id 8AF2E6B004A for ; Thu, 23 Feb 2012 21:49:13 -0500 (EST) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 9DC153EE081 for ; Fri, 24 Feb 2012 11:49:11 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 836CF45DE50 for ; Fri, 24 Feb 2012 11:49:11 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 68D7845DD74 for ; Fri, 24 Feb 2012 11:49:11 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 5B0421DB803E for ; Fri, 24 Feb 2012 11:49:11 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 1294C1DB803A for ; Fri, 24 Feb 2012 11:49:11 +0900 (JST) Date: Fri, 24 Feb 2012 11:47:48 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] mm: Enable MAP_UNINITIALIZED for archs with mmu Message-Id: <20120224114748.720ee79a.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4F468888.9090702@fb.com> References: <1326912662-18805-1-git-send-email-asharma@fb.com> <4F468888.9090702@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Arun Sharma Cc: Balbir Singh , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org On Thu, 23 Feb 2012 10:42:16 -0800 Arun Sharma wrote: > Hi Balbir, > > Thanks for reviewing. Would you change your position if I limit the > scope of the patch to a cgroup with a single address space? > > The moment the cgroup sees more than one address space (either due to > tasks getting created or being added), this optimization would be turned > off. > > More details below: > > On 2/22/12 11:45 PM, Balbir Singh wrote: > > > > So the assumption is that only apps that have access to each others > > VMA's will run in this cgroup? > > > > In a distributed computing environment, a user submits a job to the > cluster job scheduler. The job might involve multiple related > executables and might involve multiple address spaces. But they're > performing one logical task, have a single resource limit enforced by a > cgroup. > > They don't have access to each other's VMAs, but if "accidentally" one > of them comes across an uninitialized page with data from another task, > it's not a violation of the security model. > How do you handle shared resouce, file-cache ? Thanks, -Kame -- 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