io_uring: remove unnecessary barrier before reading cq head
authorStefan Bühler <source@stbuehler.de>
Wed, 24 Apr 2019 21:54:18 +0000 (23:54 +0200)
committerJens Axboe <axboe@kernel.dk>
Tue, 30 Apr 2019 15:40:02 +0000 (09:40 -0600)
commit115e12e58dbc055e98c965e3255aed7b20214f95
treebe290c72e31a400bb1462eb4cacab2e4c8e64085
parent4f7067c3fb7f2974363a28c597a41949d971af02
io_uring: remove unnecessary barrier before reading cq head

The memory operations before reading cq head are unrelated and we
don't care about their order.

Document that the control dependency in combination with READ_ONCE and
WRITE_ONCE forms a barrier we need.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c