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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2015-06-02 08:35:09 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-06-01 20:09:03 -0600 |
| commit | 419c21a3b6275d40a10901f700efcd40515b6db6 (patch) | |
| tree | d9c7c2de841bc87fb5f43a12f89052f649f22fc4 | |
| parent | 42483228d4c019ffc86b8dbea7dfbc3f9566fe7e (diff) | |
| download | lwn-419c21a3b6275d40a10901f700efcd40515b6db6.tar.gz lwn-419c21a3b6275d40a10901f700efcd40515b6db6.zip | |
null_blk: prevent timer handler running on a different CPU where started
When irqmode=2 (IRQ completion handler is timer), timer handler should
be called on the same CPU where the timer has been started.
Since completion_queues are per-cpu and the completion handler only
touches completion_queue for local CPU, we need to prevent the handler
from running on a different CPU where the timer has been started.
Otherwise, the IO cannot be completed until another completion handler
is executed on that CPU.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | drivers/block/null_blk.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 65cd61a4145e..6f0a58e7613d 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -257,7 +257,7 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd) if (llist_add(&cmd->ll_list, &cq->list)) { ktime_t kt = ktime_set(0, completion_nsec); - hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL); + hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL_PINNED); } put_cpu(); |