writeback: implement backing_dev_info->tot_write_bandwidth
authorTejun Heo <tj@kernel.org>
Fri, 22 May 2015 21:13:46 +0000 (17:13 -0400)
committerJens Axboe <axboe@fb.com>
Tue, 2 Jun 2015 14:33:35 +0000 (08:33 -0600)
commit766a9d6e60578f1ef6de71f89f022084f8bffc82
treec14261a70cdc790ffca5e82fa006fa8adf663319
parentd6c10f1fc8626dc55946f4768ae322b4c57b07dd
writeback: implement backing_dev_info->tot_write_bandwidth

cgroup writeback support needs to keep track of the sum of
avg_write_bandwidth of all wb's (bdi_writeback's) with dirty inodes to
distribute write workload.  This patch adds bdi->tot_write_bandwidth
and updates inode_wb_list_move_locked(), inode_wb_list_del_locked()
and wb_update_write_bandwidth() to adjust it as wb's gain and lose
dirty inodes and its avg_write_bandwidth gets updated.

As the update events are not synchronized with each other,
bdi->tot_write_bandwidth is an atomic_long_t.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
fs/fs-writeback.c
include/linux/backing-dev-defs.h
mm/page-writeback.c