static void io_sq_thread_stop(struct io_ring_ctx *ctx)
{
	if (ctx->sqo_thread) {
		wait_for_completion(&ctx->sq_thread_comp);
		/*
		 * The park is a bit of a work-around, without it we get
		 * warning spews on shutdown with SQPOLL set and affinity
		 * set to a single CPU.
		 */
		kthread_park(ctx->sqo_thread);
		kthread_stop(ctx->sqo_thread);
		ctx->sqo_thread = NULL;
	}
}
static void io_sq_thread_stop(struct io_ring_ctx *ctx)
{
	if (ctx->sqo_thread) {
		wait_for_completion(&ctx->sq_thread_comp);
		 
		kthread_park(ctx->sqo_thread);
		kthread_stop(ctx->sqo_thread);
		ctx->sqo_thread = NULL;
	}
}