Re: [PATCH 6/8] io_uring: add nr_ctx to record the number of ctx in a task

[Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>]

在 2021/10/27 下午10:02, Hao Xu 写道:
> This is used in the next patch for task_work batch optimization.
>
> Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
haven't done the sqpoll part. nr_ctx works for
non-sqpoll mode for now.
> ---
>   fs/io_uring.c | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index db5d9189df3a..7c6d90d693b8 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -470,6 +470,7 @@ struct io_uring_task {
>   	struct io_wq_work_list	prior_task_list;
>   	struct callback_head	task_work;
>   	bool			task_running;
> +	unsigned int		nr_ctx;
>   };
>   
>   /*
> @@ -9655,6 +9656,9 @@ static int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)
>   		mutex_lock(&ctx->uring_lock);
>   		list_add(&node->ctx_node, &ctx->tctx_list);
>   		mutex_unlock(&ctx->uring_lock);
> +		spin_lock_irq(&tctx->task_lock);
> +		tctx->nr_ctx++;
> +		spin_unlock_irq(&tctx->task_lock);
>   	}
>   	tctx->last = ctx;
>   	return 0;
> @@ -9692,6 +9696,9 @@ static __cold void io_uring_del_tctx_node(unsigned long index)
>   	mutex_lock(&node->ctx->uring_lock);
>   	list_del(&node->ctx_node);
>   	mutex_unlock(&node->ctx->uring_lock);
> +	spin_lock_irq(&tctx->task_lock);
> +	tctx->nr_ctx--;
> +	spin_unlock_irq(&tctx->task_lock);
>   
>   	if (tctx->last == node->ctx)
>   		tctx->last = NULL;