From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: [PATCH 0/2] ext4: a couple writeback path fixes Date: Tue, 31 Aug 2010 08:56:16 -0500 Message-ID: <4C7D0A00.40601@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: ext4 development Return-path: Received: from mx1.redhat.com ([209.132.183.28]:22072 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757370Ab0HaN4U (ORCPT ); Tue, 31 Aug 2010 09:56:20 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7VDuJG8001946 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 31 Aug 2010 09:56:20 -0400 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o7VDuGkZ018721 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 31 Aug 2010 09:56:19 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: I've found a couple small problems in the ext4_da_writepages path; 1) ext4_num_dirty_pages() can continue looping after max_pages is reached - this leads to wasted cpu cycles during writeback 2) bumping nr_to_write can wrap if we started with LONG_MAX - Not sure of all ramifications, but nr_to_write = -8 can't be good -Eric