From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p73BAiBE149404 for ; Wed, 3 Aug 2011 06:10:44 -0500 Received: from mx1.redhat.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 348DEB7559 for ; Wed, 3 Aug 2011 04:10:43 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id sGAkgNKH0U8By8lr for ; Wed, 03 Aug 2011 04:10:43 -0700 (PDT) Date: Wed, 3 Aug 2011 13:10:31 +0200 From: Johannes Weiner Subject: Re: [PATCH 4/8] btrfs: Warn if direct reclaim tries to writeback pages Message-ID: <20110803111031.GC27199@redhat.com> References: <1311265730-5324-1-git-send-email-mgorman@suse.de> <1311265730-5324-5-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1311265730-5324-5-git-send-email-mgorman@suse.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Mel Gorman Cc: Rik van Riel , Jan Kara , LKML , XFS , Christoph Hellwig , Linux-MM , Minchan Kim , Wu Fengguang On Thu, Jul 21, 2011 at 05:28:46PM +0100, Mel Gorman wrote: > Direct reclaim should never writeback pages. Warn if an attempt is > made. By rights, btrfs should be allowing writepage from kswapd if > it is failing to reclaim pages by any other means but it's outside > the scope of this patch. > > Signed-off-by: Mel Gorman > --- > fs/btrfs/disk-io.c | 2 ++ > fs/btrfs/inode.c | 2 ++ > 2 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 1ac8db5d..cc9c9cf 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -829,6 +829,8 @@ static int btree_writepage(struct page *page, struct writeback_control *wbc) > > tree = &BTRFS_I(page->mapping->host)->io_tree; > if (!(current->flags & PF_MEMALLOC)) { > + WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == > + PF_MEMALLOC); Since it is branch for PF_MEMALLOC being set, why not just WARN_ON_ONCE(!(current->flags & PF_KSWAPD)) instead? Minor nitpick, though, and I can understand if you just want to have the conditionals be the same in every fs. Acked-by: Johannes Weiner _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs