io_uring: provide IORING_ENTER_SQ_WAIT for SQPOLL SQ ring waits
authorJens Axboe <axboe@kernel.dk>
Thu, 3 Sep 2020 18:12:41 +0000 (12:12 -0600)
committerJens Axboe <axboe@kernel.dk>
Thu, 1 Oct 2020 02:32:33 +0000 (20:32 -0600)
commit90554200724d5b280439dc361fe7ee92fe459ea7
tree84e9f46f6ffba3498620134c8b9761c26e5d4146
parent738277adc81929b3e7c9b63fec6693868cc5f931
io_uring: provide IORING_ENTER_SQ_WAIT for SQPOLL SQ ring waits

When using SQPOLL, applications can run into the issue of running out of
SQ ring entries because the thread hasn't consumed them yet. The only
option for dealing with that is checking later, or busy checking for the
condition.

Provide IORING_ENTER_SQ_WAIT if applications want to wait on this
condition.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c
include/uapi/linux/io_uring.h