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 <mgorman@xxxxxxx> > --- > 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 <jweiner@xxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>