From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx116.postini.com [74.125.245.116]) by kanga.kvack.org (Postfix) with SMTP id 90AA56B004D for ; Tue, 15 May 2012 05:19:55 -0400 (EDT) Received: from /spool/local by e4.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 15 May 2012 05:19:54 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 1330E6E804A for ; Tue, 15 May 2012 05:19:53 -0400 (EDT) Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q4F9JqqC122806 for ; Tue, 15 May 2012 05:19:52 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q4F9JqTt032592 for ; Tue, 15 May 2012 05:19:52 -0400 Date: Tue, 15 May 2012 17:19:49 +0800 From: Gavin Shan Subject: Re: [PATCH] mm/slab: remove duplicate check Message-ID: <20120515091949.GA4887@shangw> Reply-To: Gavin Shan References: <1336727769-19555-1-git-send-email-shangw@linux.vnet.ibm.com> <20120514204219.GC1406@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120514204219.GC1406@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: linux-mm@kvack.org, akpm@linux-foundation.org >> While allocateing pages using buddy allocator, the compound page >> is probably split up to free pages. Under the circumstance, the >> compound page should be destroied by function destroy_compound_page(). >> However, there has duplicate check to judge if the page is compound >> one. >> >> The patch removes the duplicate check since the function compound_order() >> will returns 0 while the page hasn't PG_head set in function destroy_compound_page(). >> That's to say, the function destroy_compound_page() needn't check >> PG_head any more through function PageHead(). >> >> Signed-off-by: Gavin Shan > >Looks good! > >But the slab in the subject suggests it would not affect other parts >of mm, while it actually affects THP, too. Should probably be >removed? > >Acked-by: Johannes Weiner > Thanks for looking into this, Johannes :-) I'm not sure I should change the subject to "mm: xxx" and resend it since it has been put into linux-mm next tree as the maillist mm-commits told me. By the way, I even don't know how linux-mm next got sychronized with linux mainline yet :-) Thanks, Gavin -- 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