From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 1A1546B004A for ; Tue, 12 Jul 2011 14:01:26 -0400 (EDT) Date: Tue, 12 Jul 2011 20:01:20 +0200 From: Andrea Arcangeli Subject: Re: mm: do_wp_page recheck PageKsm after obtaining the page_lock, pte_same not enough Message-ID: <20110712180120.GU23227@redhat.com> References: <20110712165003.GP23227@redhat.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: Nai Xia Cc: Hugh Dickins , linux-mm@kvack.org, Marcelo Tosatti , Johannes Weiner On Wed, Jul 13, 2011 at 01:48:10AM +0800, Nai Xia wrote: > I think in this case we should copy the page instead of going to unlock. > > And I think reuse_swap_page() has checked the PageKsm(page) inside and > in this case it will go to the copy path already? yes this is why it's unnecessary, I've been a bit in a paranoid mode on this code lately, one more check wouldn't have hurted but it's definitely unnecessary so please ignore... -- 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