io_uring: prevent sq_thread from spinning when it should stop
authorStefano Garzarella <sgarzare@redhat.com>
Fri, 21 Feb 2020 15:42:16 +0000 (16:42 +0100)
committerJens Axboe <axboe@kernel.dk>
Fri, 21 Feb 2020 16:16:10 +0000 (09:16 -0700)
commit7143b5ac5750f404ff3a594b34fdf3fc2f99f828
treed6bf0edaaf6f0f994d2043d91a91644b2e6ca461
parent929a3af90f0f4bd7132d83552c1a98c83f60ef7e
io_uring: prevent sq_thread from spinning when it should stop

This patch drops 'cur_mm' before calling cond_resched(), to prevent
the sq_thread from spinning even when the user process is finished.

Before this patch, if the user process ended without closing the
io_uring fd, the sq_thread continues to spin until the
'sq_thread_idle' timeout ends.

In the worst case where the 'sq_thread_idle' parameter is bigger than
INT_MAX, the sq_thread will spin forever.

Fixes: 6c271ce2f1d5 ("io_uring: add submission polling")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c