Frederic Weisbecker 09eb47a7c5 kill-the-bkl/reiserfs: reduce number of contentions in search_by_key()
search_by_key() is a central function in reiserfs which searches
the patch in the fs tree from the root to a node given its key.

It is the function that is most requesting the write lock
because it's a path very often used.

Also we forget to release the lock while reading the next tree node,
making us holding the lock in a wasteful way.

Then we release the lock while reading the current node and its childs,
all-in-one. It should be safe because we have a reference to these
blocks and even if we read a block that will be concurrently changed,
we have an fs_changed check later that will make us retry the path from
the root.

[ Impact: release the write lock while unused in a hot path ]

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:19 +02:00
..
2009-07-12 12:22:34 -07:00
2009-06-11 21:36:14 -04:00
2009-06-11 21:36:01 -04:00
2009-07-12 12:22:34 -07:00
2009-08-21 10:09:44 +02:00
2009-06-24 08:15:24 -04:00
2009-07-14 12:28:43 -05:00
2009-06-17 00:36:36 -04:00
2009-07-12 12:22:34 -07:00
2009-09-05 13:41:08 -07:00
2009-07-12 12:22:34 -07:00
2009-07-12 12:22:34 -07:00
2009-07-12 12:22:34 -07:00
2009-07-12 12:22:34 -07:00
2009-07-12 12:22:34 -07:00
2009-07-10 19:18:59 -07:00
2009-07-12 12:22:34 -07:00
2009-06-15 21:44:43 -07:00
2009-07-12 12:22:34 -07:00
2009-06-15 21:44:43 -07:00
2009-06-11 21:36:13 -04:00
2009-08-18 16:31:13 -07:00
2009-06-11 21:36:12 -04:00
2009-07-30 17:31:23 +02:00
2009-06-11 21:36:07 -04:00
2009-07-12 12:22:34 -07:00
2009-06-17 00:36:37 -04:00
2009-07-12 12:22:34 -07:00
2009-06-18 13:03:46 -07:00
2009-06-30 18:55:58 -07:00
2009-07-01 11:14:28 -07:00
2009-07-12 12:22:34 -07:00
2009-06-11 21:36:06 -04:00
2009-06-18 13:03:41 -07:00
2009-07-12 12:22:34 -07:00
2009-08-07 14:38:29 -03:00
2009-06-11 21:36:07 -04:00
2009-07-14 12:34:17 +09:00
2009-09-07 11:54:58 +10:00
2009-04-20 23:02:52 -04:00
2009-06-11 21:36:02 -04:00