From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 8A2B46B0123 for ; Fri, 6 Mar 2009 14:39:35 -0500 (EST) Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id A804782D7C2 for ; Fri, 6 Mar 2009 14:45:10 -0500 (EST) Received: from smtp.ultrahosting.com ([74.213.175.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0U8MM5It+m9F for ; Fri, 6 Mar 2009 14:45:06 -0500 (EST) Received: from qirst.com (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id D15C982D7B6 for ; Fri, 6 Mar 2009 14:45:02 -0500 (EST) Date: Fri, 6 Mar 2009 14:28:50 -0500 (EST) From: Christoph Lameter Subject: Re: possible bug in find_get_pages In-Reply-To: <20090306192625.GA3267@linux.intel.com> Message-ID: References: <20090306192625.GA3267@linux.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: mark gross Cc: linux-mm@kvack.org, npiggin@suse.de List-ID: On Fri, 6 Mar 2009, mark gross wrote: > It seems that page->_count == 0 at some point on some overnight runs > with locks the system into a tight loop from the repeat: and a goto > repeat in find_get_pages. A page with ref count zero should not be in any mapping. If the page is in a mapping then the page is used. Therefore the refcount should be > 0. If there is a page with zero refcount and its in a mapping then something erroneously decreased the refcount. Nick wrote the code so I CCed him. -- 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