null_blk: prevent timer handler running on a different CPU where started
authorAkinobu Mita <akinobu.mita@gmail.com>
Mon, 1 Jun 2015 23:35:09 +0000 (08:35 +0900)
committerJens Axboe <axboe@fb.com>
Tue, 2 Jun 2015 02:09:03 +0000 (20:09 -0600)
commit419c21a3b6275d40a10901f700efcd40515b6db6
treed9c7c2de841bc87fb5f43a12f89052f649f22fc4
parent42483228d4c019ffc86b8dbea7dfbc3f9566fe7e
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>
drivers/block/null_blk.c