From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 007868D0039 for ; Wed, 9 Mar 2011 02:11:19 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id E82E43EE0AE for ; Wed, 9 Mar 2011 16:11:16 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id CCFEC45DE50 for ; Wed, 9 Mar 2011 16:11:16 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id B63ED45DE4F for ; Wed, 9 Mar 2011 16:11:16 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id A73FF1DB803B for ; Wed, 9 Mar 2011 16:11:16 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 711F31DB802F for ; Wed, 9 Mar 2011 16:11:16 +0900 (JST) From: KOSAKI Motohiro Subject: Re: THP, rmap and page_referenced_one() In-Reply-To: <4D7635DA.9030707@redhat.com> References: <20110308113245.GR25641@random.random> <4D7635DA.9030707@redhat.com> Message-Id: <20110309161132.0409.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Date: Wed, 9 Mar 2011 16:11:15 +0900 (JST) Sender: owner-linux-mm@kvack.org List-ID: To: Rik van Riel Cc: kosaki.motohiro@jp.fujitsu.com, Andrea Arcangeli , Michel Lespinasse , Minchan Kim , Hugh Dickins , Andrew Morton , linux-mm > On 03/08/2011 06:32 AM, Andrea Arcangeli wrote: > > > Subject: thp: fix page_referenced to modify mapcount/vm_flags only if page is found > > > > From: Andrea Arcangeli > > > > When vmscan.c calls page_referenced, if an anon page was created before a > > process forked, rmap will search for it in both of the processes, even though > > one of them might have since broken COW. If the child process mlocks the vma > > where the COWed page belongs to, page_referenced() running on the page mapped > > by the parent would lead to *vm_flags getting VM_LOCKED set erroneously (leading > > to the references on the parent page being ignored and evicting the parent page > > too early). > > > Signed-off-by: Andrea Arcangeli > > Reported-by: Michel Lespinasse > > Reviewed-by: Rik van Riel Thank you, Andrea. Reviewed-by: KOSAKI Motohiro -- 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