2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Nick Piggin commit 515f4a037fb9ab736f8bad733fcd2ffd350cf265 upstream. In write_cache_pages, if we get stuck behind another process that is cleaning pages, we will be forced to wait for them to finish, then perform our own writeout (if it was redirtied during the long wait), then wait for that. If a page under writeout is still clean, we can skip waiting for it (if we're part of a data integrity sync, we'll be waiting for all writeout pages afterwards, so we'll still be waiting for the other guy's write that's cleaned the page). Signed-off-by: Nick Piggin Cc: Chris Mason Cc: Dave Chinner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page-writeback.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -948,11 +948,20 @@ continue_unlock: goto continue_unlock; } - if (wbc->sync_mode != WB_SYNC_NONE) - wait_on_page_writeback(page); + if (!PageDirty(page)) { + /* someone wrote it for us */ + goto continue_unlock; + } + + if (PageWriteback(page)) { + if (wbc->sync_mode != WB_SYNC_NONE) + wait_on_page_writeback(page); + else + goto continue_unlock; + } - if (PageWriteback(page) || - !clear_page_dirty_for_io(page)) + BUG_ON(PageWriteback(page)); + if (!clear_page_dirty_for_io(page)) goto continue_unlock; ret = (*writepage)(page, wbc, data); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/