Re: [PATCH v6 1/5] io_uring: introduce callback driven main loop

[Jens Axboe <axboe@kernel.dk>]

On 2/11/26 12:04 PM, Pavel Begunkov wrote:
> +static int __io_run_loop(struct io_ring_ctx *ctx)
> +{
> +	struct iou_loop_state ls = {};
> +
> +	while (true) {
> +		unsigned nr_wait;
> +		int step_res;
> +
> +		if (unlikely(!ctx->loop_step))
> +			return -EFAULT;
> +
> +		step_res = ctx->loop_step(ctx, &ls.p);
> +		if (step_res == IOU_LOOP_STOP)
> +			break;
> +		if (step_res != IOU_LOOP_CONTINUE)
> +			return -EINVAL;
> +
> +		nr_wait = io_loop_nr_cqes(ctx, &ls);
> +		if (nr_wait > 0)
> +			io_loop_wait(ctx, &ls, nr_wait);
> +
> +		if (task_work_pending(current)) {
> +			mutex_unlock(&ctx->uring_lock);
> +			io_run_task_work();
> +			mutex_lock(&ctx->uring_lock);
> +		}
> +		if (unlikely(task_sigpending(current)))
> +			return -EINTR;
> +
> +		nr_wait = max(nr_wait, 0);
> +		io_run_local_work_locked(ctx, nr_wait);
> +
> +		if (READ_ONCE(ctx->check_cq) & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
> +			io_cqring_do_overflow_flush(ctx);

We need a __io_cqring_do_overflow_flush() or similar here that already
has ->uring_lock held. Or The same dropping/regetting of the lock as is
done for io_run_task_work().

-- 
Jens Axboe