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: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 0ae9ecadf295ce0b25e9440a861bb917a5f1333a..e05f996d088f17437834bcb96f4987d257773ab0 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -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 @@ loop:
                __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));

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a4bce17af506bccbf4aebcb828da8b3761d3d7c3..05adc4887ef38227e50b899986a82b83edc17c44 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -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);

diff --git a/kernel/fork.c b/kernel/fork.c
index 72e444cd0ffed29272df8ceafbf2501e3205e270..d3171e8e88e5d4af93ab1fa21a2dfe4c41b67292 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -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;
 }