From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx195.postini.com [74.125.245.195]) by kanga.kvack.org (Postfix) with SMTP id 309B56B0179 for ; Tue, 26 Jun 2012 05:05:50 -0400 (EDT) Received: by dakp5 with SMTP id p5so8027714dak.14 for ; Tue, 26 Jun 2012 02:05:49 -0700 (PDT) Date: Tue, 26 Jun 2012 02:05:47 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 11/11] protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombs In-Reply-To: <4FE9765D.2050301@parallels.com> Message-ID: References: <1340633728-12785-1-git-send-email-glommer@parallels.com> <1340633728-12785-12-git-send-email-glommer@parallels.com> <4FE96358.6080601@parallels.com> <4FE9765D.2050301@parallels.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Frederic Weisbecker , Pekka Enberg , Michal Hocko , Johannes Weiner , Christoph Lameter , devel@openvz.org, kamezawa.hiroyu@jp.fujitsu.com, Tejun Heo , Pekka Enberg , Suleiman Souhlal , Frederic Weisbecker On Tue, 26 Jun 2012, Glauber Costa wrote: > > Right, because I'm sure that __GFP_KMEMCG will be used in additional > > places outside of this patchset and it will be a shame if we have to > > always add #ifdef's. I see no reason why we would care if __GFP_KMEMCG > > was used when CONFIG_CGROUP_MEM_RES_CTLR_KMEM=n with the semantics that it > > as in this patchset. It's much cleaner by making it 0x0 when disabled. > > > > What I can do, instead, is to WARN_ON conditionally to the config option in > the page allocator, and make sure no one is actually passing the flag in that > case. > I don't think adding a conditional to the page allocator's fastpath when CONFIG_CGROUP_MEM_RES_CTLR_KMEM=n is appropriate. I don't understand why this can't be 0x0 for such a configuration, __GFP_KMEM certainly means nothing when we don't have it enabled so how is this different at all from kmemcheck? -- 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