From 9e094383b60066996fbc3b53891324e5d2ec858d Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 7 Jul 2010 13:24:08 +1000 Subject: writeback: Add tracing to write_cache_pages Add a trace event to the ->writepage loop in write_cache_pages to give visibility into how the ->writepage call is changing variables within the writeback control structure. Of most interest is how wbc->nr_to_write changes from call to call, especially with filesystems that write multiple pages in ->writepage. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- mm/page-writeback.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/page-writeback.c') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index d556cd829af6..3d2111a22236 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -933,6 +933,7 @@ continue_unlock: if (!clear_page_dirty_for_io(page)) goto continue_unlock; + trace_wbc_writepage(wbc, mapping->backing_dev_info); ret = (*writepage)(page, wbc, data); if (unlikely(ret)) { if (ret == AOP_WRITEPAGE_ACTIVATE) { -- cgit v1.2.3