diff options
| author | Tejun Heo <tj@kernel.org> | 2014-11-04 13:52:27 -0500 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-11-04 14:49:31 -0700 |
| commit | f3af020b9a8d298022b811a19719df0cf461efa5 (patch) | |
| tree | 7468b9e6077738b941c89433d491662c7b8da8b4 /lib/find_next_bit.c | |
| parent | ece9c72accdc45c3a9484dacb1125ce572647288 (diff) | |
blk-mq: make mq_queue_reinit_notify() freeze queues in parallel
q->mq_usage_counter is a percpu_ref which is killed and drained when
the queue is frozen. On a CPU hotplug event, blk_mq_queue_reinit()
which involves freezing the queue is invoked on all existing queues.
Because percpu_ref killing and draining involve a RCU grace period,
doing the above on one queue after another may take a long time if
there are many queues on the system.
This patch splits out initiation of freezing and waiting for its
completion, and updates blk_mq_queue_reinit_notify() so that the
queues are frozen in parallel instead of one after another. Note that
freezing and unfreezing are moved from blk_mq_queue_reinit() to
blk_mq_queue_reinit_notify().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'lib/find_next_bit.c')
0 files changed, 0 insertions, 0 deletions