Commit 16efa4fc authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: allow IO worker threads to be frozen 



With the freezer using the proper signaling to notify us of when it's
time to freeze a thread, we can re-enable normal freezer usage for the
IO threads. Ensure that SQPOLL, io-wq, and the io-wq manager call
try_to_freeze() appropriately, and remove the default setting of
PF_NOFREEZE from create_io_thread().

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 15b2219f

fs/io-wq.c

+5 −1
Original line number Diff line number Diff line
@@ -488,6 +488,8 @@ static int io_wqe_worker(void *data) 
	set_task_comm(current, buf);



	while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {

		long ret;



		set_current_state(TASK_INTERRUPTIBLE);

loop:

		raw_spin_lock_irq(&wqe->lock);
@@ -498,7 +500,8 @@ static int io_wqe_worker(void *data) 
		__io_worker_idle(wqe, worker);

		raw_spin_unlock_irq(&wqe->lock);

		io_flush_signals();

		if (schedule_timeout(WORKER_IDLE_TIMEOUT))

		ret = schedule_timeout(WORKER_IDLE_TIMEOUT);

		if (try_to_freeze() || ret)

			continue;

		if (fatal_signal_pending(current))

			break;
@@ -709,6 +712,7 @@ static int io_wq_manager(void *data) 
		set_current_state(TASK_INTERRUPTIBLE);

		io_wq_check_workers(wq);

		schedule_timeout(HZ);

		try_to_freeze();

		if (fatal_signal_pending(current))

			set_bit(IO_WQ_BIT_EXIT, &wq->state);

	} while (!test_bit(IO_WQ_BIT_EXIT, &wq->state));

fs/io_uring.c

+1 −0
Original line number Diff line number Diff line
@@ -6752,6 +6752,7 @@ static int io_sq_thread(void *data) 


			up_read(&sqd->rw_lock);

			schedule();

			try_to_freeze();

			down_read(&sqd->rw_lock);

			list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)

				io_ring_clear_wakeup_flag(ctx);

kernel/fork.c

+0 −1
Original line number Diff line number Diff line
@@ -2436,7 +2436,6 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) 
	if (!IS_ERR(tsk)) {

		sigfillset(&tsk->blocked);

		sigdelsetmask(&tsk->blocked, sigmask(SIGKILL));

		tsk->flags |= PF_NOFREEZE;

	}

	return tsk;

}