blkcg: kill unused field nr_undestroyed_grps

'nr_undestroyed_grps' in struct throtl_data was used to count
the number of throtl_grp related with throtl_data, but now
throtl_grp is tracked by blkcg_gq, so it is useless anymore.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 0 insertions, 5 deletions

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 47a3e540631a..c5494e403239 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -145,11 +145,6 @@ struct throtl_data
         /* Total Number of queued bios on READ and WRITE lists */
         unsigned int nr_queued[2];
 
-        /*
-         * number of total undestroyed groups
-         */
-        unsigned int nr_undestroyed_grps;
-
         /* Work for dispatching throttled bios */
         struct work_struct dispatch_work;
 };