From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753955AbXFKXev (ORCPT ); Mon, 11 Jun 2007 19:34:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752758AbXFKXeo (ORCPT ); Mon, 11 Jun 2007 19:34:44 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:35453 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751023AbXFKXeo (ORCPT ); Mon, 11 Jun 2007 19:34:44 -0400 Date: Mon, 11 Jun 2007 16:34:33 -0700 From: Andrew Morton To: Jens Axboe Cc: linux-kernel@vger.kernel.org Subject: Re: splice: move balance_dirty_pages_ratelimited() outside of splice actor Message-Id: <20070611163433.dbc541ec.akpm@linux-foundation.org> In-Reply-To: <200706112159.l5BLxF5x004043@hera.kernel.org> References: <200706112159.l5BLxF5x004043@hera.kernel.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 11 Jun 2007 21:59:15 GMT Linux Kernel Mailing List wrote: > Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=20d698db67059a63d217030dfd02872cb5f88dfb > Commit: 20d698db67059a63d217030dfd02872cb5f88dfb > Parent: 17374ff1aa9ce2a0597416a16729474b538af443 > Author: Jens Axboe > AuthorDate: Tue Jun 5 11:05:11 2007 +0200 > Committer: Jens Axboe > CommitDate: Fri Jun 8 08:33:59 2007 +0200 > > splice: move balance_dirty_pages_ratelimited() outside of splice actor > > I've seen inode related deadlocks, so move this call outside of the > actor itself, which may hold the inode lock. > eh? If the pipe_to_file() caller holds inode_lock, our problems are large. I doubt if that's true, so what problem is this patch really fixing?? > --- > fs/splice.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/fs/splice.c b/fs/splice.c > index b78a7f0..6349d31 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -652,7 +652,6 @@ find_page: > * accessed, we are now done! > */ > mark_page_accessed(page); > - balance_dirty_pages_ratelimited(mapping); > out: > page_cache_release(page); > unlock_page(page); > @@ -823,6 +822,7 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out, > if (err) > ret = err; > } > + balance_dirty_pages_ratelimited(mapping); > } > > return ret; > @@ -876,6 +876,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, > if (err) > ret = err; > } > + balance_dirty_pages_ratelimited(mapping); > } > balance_dirty_pages_ratelimited() is supposed to be called once-per-dirtied-page. This caller can dirty an arbitrarily large amount of memory and hence should use balance_dirty_pages_ratelimited_nr(). As things stand, a large splice() could potentially cause the dirty limits to be exceeded. btw, can we please arrange to get patches reviewed prior to them being merged?