From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx167.postini.com [74.125.245.167]) by kanga.kvack.org (Postfix) with SMTP id 47FDA6B005D for ; Fri, 28 Sep 2012 11:14:13 -0400 (EDT) Message-ID: <5065BEBF.1010705@redhat.com> Date: Fri, 28 Sep 2012 11:14:07 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] thp: avoid VM_BUG_ON page_count(page) false positives in __collapse_huge_page_copy References: <1348835731-27474-1-git-send-email-aarcange@redhat.com> In-Reply-To: <1348835731-27474-1-git-send-email-aarcange@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Linus Torvalds , Andrew Morton , linux-mm@kvack.org, Johannes Weiner , Hugh Dickins , Mel Gorman , Petr Holasek On 09/28/2012 08:35 AM, Andrea Arcangeli wrote: > Speculative cache pagecache lookups can elevate the refcount from > under us, so avoid the false positive. If the refcount is < 2 we'll be > notified by a VM_BUG_ON in put_page_testzero as there are two > put_page(src_page) in a row before returning from this function. > > Signed-off-by: Andrea Arcangeli Reviewed-by: Rik van Riel -- All rights reversed -- 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/ . Don't email: email@kvack.org