From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx170.postini.com [74.125.245.170]) by kanga.kvack.org (Postfix) with SMTP id 59BE16B004A for ; Fri, 24 Feb 2012 14:27:03 -0500 (EST) Message-ID: <4F47E47B.3000409@fb.com> Date: Fri, 24 Feb 2012 11:26:51 -0800 From: Arun Sharma MIME-Version: 1.0 Subject: Re: [PATCH] mm: Enable MAP_UNINITIALIZED for archs with mmu References: <1326912662-18805-1-git-send-email-asharma@fb.com> <4F468888.9090702@fb.com> <20120224114748.720ee79a.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20120224114748.720ee79a.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Balbir Singh , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org On 2/23/12 6:47 PM, KAMEZAWA Hiroyuki wrote: >> >> 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 ? > From a security perspective or a resource limit perspective? Security: all processes in the cgroup run with the same uid and have the same access to the filesystem. Multiple address spaces in a cgroup can be thought of as an implementation detail. Resource limit: We don't have strict enforcement right now. There is a desire to include everything (file cache, slab memory) in the job's memory resource limit. -Arun -- 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