Re: [PATCH 4/8] btrfs: Warn if direct reclaim tries to writeback pages
From: Johannes Weiner <hidden>
Date: 2011-08-03 11:10:59
Also in:
linux-xfs, lkml
On Thu, Jul 21, 2011 at 05:28:46PM +0100, Mel Gorman wrote:
quoted hunk ↗ jump to hunk
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@suse.de> --- 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 <redacted> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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@kvack.org"> email@kvack.org </a>