From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx121.postini.com [74.125.245.121]) by kanga.kvack.org (Postfix) with SMTP id 817766B004A for ; Wed, 7 Mar 2012 05:39:13 -0500 (EST) Received: by vcbfk14 with SMTP id fk14so6935015vcb.14 for ; Wed, 07 Mar 2012 02:39:12 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20120307002616.GP13462@redhat.com> References: <1330594374-13497-1-git-send-email-lliubbo@gmail.com> <20120307001148.GO13462@redhat.com> <20120307002616.GP13462@redhat.com> Date: Wed, 7 Mar 2012 18:39:12 +0800 Message-ID: Subject: Re: [PATCH 1/2] ksm: clean up page_trans_compound_anon_split From: Bob Liu Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Hugh Dickins , akpm@linux-foundation.org, rientjes@google.com, kamezawa.hiroyu@jp.fujitsu.com, minchan.kim@gmail.com, linux-mm@kvack.org Hi Andrea, On Wed, Mar 7, 2012 at 8:26 AM, Andrea Arcangeli wrot= e: > On Wed, Mar 07, 2012 at 01:11:48AM +0100, Andrea Arcangeli wrote: >> (the function was invoked only on compound pages in the first place). > > BTW, most certainly I did at some point this change: > > - =C2=A0 =C2=A0 =C2=A0 if (page_trans_compound_anon_split(page)) > + =C2=A0 =C2=A0 =C2=A0 if (PageTransCompound(page) && page_trans_compound= _anon_split(page)) > > Before doing this change, the "cleaned up" version would have been > broken. > I think this patch may still break the origin meaning. In case PageTransCompound(page) but !PageAnon(head) after this cleanup, page_trans_compound_anon_split(page) will return 1 instead of 0 which will cause following PageAnon check to a compounded page. So please just ignore this cleanup. Sorry for my noise. Hugh, Thank you for your review also. --=20 Regards, --Bob -- 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