writeback: Add tracing to write_cache_pages
authorDave Chinner <dchinner@redhat.com>
Wed, 7 Jul 2010 03:24:08 +0000 (13:24 +1000)
committerJens Axboe <jaxboe@fusionio.com>
Sat, 7 Aug 2010 16:24:26 +0000 (18:24 +0200)
commit9e094383b60066996fbc3b53891324e5d2ec858d
treea3f4af7e60781f62b52dcfddd2032c3bbf933644
parent028c2dd184c097809986684f2f0627eea5529fea
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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
include/trace/events/writeback.h
mm/page-writeback.c