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| author | Tejun Heo | 2014-11-04 19:52:27 +0100 |
|---|---|---|
| committer | Jens Axboe | 2014-11-04 22:49:31 +0100 |
| commit | f3af020b9a8d298022b811a19719df0cf461efa5 (patch) | |
| tree | 7468b9e6077738b941c89433d491662c7b8da8b4 /block/scsi_ioctl.c | |
| parent | block: Fix computation of merged request priority (diff) | |
| download | kernel-qcow2-linux-f3af020b9a8d298022b811a19719df0cf461efa5.tar.gz kernel-qcow2-linux-f3af020b9a8d298022b811a19719df0cf461efa5.tar.xz kernel-qcow2-linux-f3af020b9a8d298022b811a19719df0cf461efa5.zip | |
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 'block/scsi_ioctl.c')
0 files changed, 0 insertions, 0 deletions