crush: add note about r in recursive choose

Reflects ceph.git commit 4551fee9ad89d0427ed865d766d0d44004d3e3e1.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
This commit is contained in:
Ilya Dryomov 2013-12-24 21:19:25 +02:00
parent 9a3b490a20
commit 3102b0a5b4

View File

@ -514,6 +514,14 @@ static void crush_choose_indep(const struct crush_map *map,
/* choose through intervening buckets */
for (;;) {
/* note: we base the choice on the position
* even in the nested call. that means that
* if the first layer chooses the same bucket
* in a different position, we will tend to
* choose a different item in that bucket.
* this will involve more devices in data
* movement and tend to distribute the load.
*/
r = rep;
/* be careful */