diff options
authorAkinobu Mita <>2015-06-02 08:35:09 +0900
committerJens Axboe <>2015-06-01 20:09:03 -0600
commit419c21a3b6275d40a10901f700efcd40515b6db6 (patch)
parent42483228d4c019ffc86b8dbea7dfbc3f9566fe7e (diff)
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 <> Cc: Jens Axboe <> Signed-off-by: Jens Axboe <>
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);