From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx119.postini.com [74.125.245.119]) by kanga.kvack.org (Postfix) with SMTP id EF5B26B002C for ; Mon, 5 Mar 2012 09:48:37 -0500 (EST) Date: Mon, 5 Mar 2012 08:48:33 -0600 (CST) From: Christoph Lameter Subject: Re: [PATCH -next] slub: set PG_slab on all of slab pages In-Reply-To: <20120304103446.GA9267@barrios> Message-ID: References: <1330505674-31610-1-git-send-email-namhyung.kim@lge.com> <20120304103446.GA9267@barrios> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Namhyung Kim , Pekka Enberg , Matt Mackall , Namhyung Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Sun, 4 Mar 2012, Minchan Kim wrote: > I read this thread and I feel the we don't reach right point. > I think it's not a compound page problem. > We can face above problem where we allocates big order page without __GFP_COMP > and free middle page of it. Yes we can do that and doing such a thing seems to be more legitimate since one could argue that the user did not request an atomic allocation unit from the page allocator and therefore the freeing of individual pages in that group is permissible. If memory serves me right we do that sometimes. However if compound pages are requested then such an atomic allocation unit *was* requested and the page allocator should not allow to free individual pages. -- 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