From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx146.postini.com [74.125.245.146]) by kanga.kvack.org (Postfix) with SMTP id 95D496B005A for ; Fri, 21 Sep 2012 16:07:38 -0400 (EDT) Received: by pbbro12 with SMTP id ro12so9047794pbb.14 for ; Fri, 21 Sep 2012 13:07:37 -0700 (PDT) Date: Fri, 21 Sep 2012 13:07:33 -0700 From: Tejun Heo Subject: Re: [PATCH v3 09/16] sl[au]b: always get the cache from its page in kfree Message-ID: <20120921200733.GM7264@google.com> References: <1347977530-29755-1-git-send-email-glommer@parallels.com> <1347977530-29755-10-git-send-email-glommer@parallels.com> <00000139d9fe8595-8905906d-18ed-4d41-afdb-f4c632c2d50a-000000@email.amazonses.com> <5059777E.8060906@parallels.com> <505C33D3.5000202@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Pekka Enberg Cc: Glauber Costa , Christoph Lameter , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org, linux-mm@kvack.org, Suleiman Souhlal , Frederic Weisbecker , Mel Gorman , David Rientjes , Ingo Molnar , Steven Rostedt Hello, On Fri, Sep 21, 2012 at 12:41:52PM +0300, Pekka Enberg wrote: > > I am already using static keys extensively in this patchset, and that is > > how I intend to handle this particular case. > > Cool. > > The key point here is that !CONFIG_MEMCG_KMEM should have exactly *zero* > performance impact and CONFIG_MEMCG_KMEM disabled at runtime should have > absolute minimal impact. Not necessarily disagreeing, but I don't think it's helpful to set the bar impossibly high. Even static_key doesn't have "exactly *zero*" impact. Let's stick to as minimal as possible when not in use and reasonable in use. And, yeah, this one can be easily solved by using static_key. Thanks. -- tejun -- 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