From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753522Ab1HJKs1 (ORCPT ); Wed, 10 Aug 2011 06:48:27 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57307 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752378Ab1HJKr0 (ORCPT ); Wed, 10 Aug 2011 06:47:26 -0400 From: Mel Gorman To: Linux-MM Cc: LKML , XFS , Dave Chinner , Christoph Hellwig , Johannes Weiner , Wu Fengguang , Jan Kara , Rik van Riel , Minchan Kim , Mel Gorman Subject: [PATCH 3/7] xfs: Warn if direct reclaim tries to writeback pages Date: Wed, 10 Aug 2011 11:47:16 +0100 Message-Id: <1312973240-32576-4-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.3.4 In-Reply-To: <1312973240-32576-1-git-send-email-mgorman@suse.de> References: <1312973240-32576-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Direct reclaim should never writeback pages. For now, handle the situation and warn about it. Ultimately, this will be a BUG_ON. Signed-off-by: Mel Gorman --- fs/xfs/linux-2.6/xfs_aops.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 79ce38b..afea9cd 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -930,11 +930,10 @@ xfs_vm_writepage( * random callers for direct reclaim or memcg reclaim. We explicitly * allow reclaim from kswapd as the stack usage there is relatively low. * - * This should really be done by the core VM, but until that happens - * filesystems like XFS, btrfs and ext4 have to take care of this - * by themselves. + * This should never happen except in the case of a VM regression so + * warn about it. */ - if ((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC) + if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC)) goto redirty; /* -- 1.7.3.4