From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755108AbYAILLc (ORCPT ); Wed, 9 Jan 2008 06:11:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751558AbYAILLZ (ORCPT ); Wed, 9 Jan 2008 06:11:25 -0500 Received: from mail.gmx.net ([213.165.64.20]:37957 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751424AbYAILLX (ORCPT ); Wed, 9 Jan 2008 06:11:23 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1/65vcqTAT6DoH9BKQZt9J7OpzjWkBHyKr/G3N5r4 3WTg/XmG3PwzBJ Subject: Re: [vm] writing to UDF DVD+RW (/dev/sr0) while under memory pressure: box ==> doorstop From: Mike Galbraith To: Andrew Morton Cc: LKML , linux-mm In-Reply-To: <1199806071.4174.2.camel@homer.simson.net> References: <1199447212.4529.13.camel@homer.simson.net> <1199612533.4384.54.camel@homer.simson.net> <1199642470.3927.12.camel@homer.simson.net> <20080106122954.d8f04c98.akpm@linux-foundation.org> <1199790316.4094.57.camel@homer.simson.net> <20080108033801.40d0043a.akpm@linux-foundation.org> <1199805713.3571.12.camel@homer.simson.net> <1199806071.4174.2.camel@homer.simson.net> Content-Type: text/plain Date: Wed, 09 Jan 2008 12:11:20 +0100 Message-Id: <1199877080.4340.19.camel@homer.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-01-08 at 16:27 +0100, Mike Galbraith wrote: > On Tue, 2008-01-08 at 16:21 +0100, Mike Galbraith wrote: > > On Tue, 2008-01-08 at 03:38 -0800, Andrew Morton wrote: > > > > > > Well. From your earlier trace it appeared that something was causing > > > the filesystem to perform synchronous inode writes - sync_dirty_buffer() was > > > called. > > > > > > This will cause many more seeks than would occur if we were doing full > > > delayed writing, with obvious throughput implications. > > > > Yes, with UDF, the IO was _incredibly_ slow. With ext2, it was better, > > though still very bad. I tested with that other OS, and it gets ~same > > throughput with UDF as I got with ext2 (ick). > > > > UDF does udf_clear_inode() -> write_inode_now(inode, 1) > > > > I suppose I could try write_inode_now(inode, 0). Might unstick the box. > > (nope, still sync, UDF still deadly) write_inode_now() is a fibber. The below seems to fix it in that writes dribbling to the DVD+RW at the whopping 1 to 10 pages/sec I'm seeing no longer turn box into a doorstop. It's probably busted as heck. Think I'll cc linux-mm, and go find something safer to play with. diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 0fca820..f1cce24 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -657,7 +657,7 @@ int write_inode_now(struct inode *inode, int sync) int ret; struct writeback_control wbc = { .nr_to_write = LONG_MAX, - .sync_mode = WB_SYNC_ALL, + .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, .range_start = 0, .range_end = LLONG_MAX, }; diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 6ff8151..d1fc116 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -117,7 +117,7 @@ void udf_clear_inode(struct inode *inode) udf_discard_prealloc(inode); udf_truncate_tail_extent(inode); unlock_kernel(); - write_inode_now(inode, 1); + write_inode_now(inode, 0); } kfree(UDF_I_DATA(inode)); UDF_I_DATA(inode) = NULL;