Re: [PATCH for-5.15] io-wq: move nr_running and worker_refs out of wqe->lock protection

[Hao Xu <haoxu@linux.alibaba.com>]

在 2021/8/10 下午8:55, Hao Xu 写道:
ping
> We don't need to protect nr_running and worker_refs by wqe->lock, so
> narrow the range of raw_spin_lock_irq - raw_spin_unlock_irq
> 
> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
> ---
>   fs/io-wq.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/io-wq.c b/fs/io-wq.c
> index 4ce83bb48021..8da9bb103916 100644
> --- a/fs/io-wq.c
> +++ b/fs/io-wq.c
> @@ -256,16 +256,17 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
>   
>   		raw_spin_lock_irq(&wqe->lock);
>   		if (acct->nr_workers < acct->max_workers) {
> -			atomic_inc(&acct->nr_running);
> -			atomic_inc(&wqe->wq->worker_refs);
>   			if (!acct->nr_workers)
>   				first = true;
>   			acct->nr_workers++;
>   			do_create = true;
>   		}
>   		raw_spin_unlock_irq(&wqe->lock);
> -		if (do_create)
> +		if (do_create) {
> +			atomic_inc(&acct->nr_running);
> +			atomic_inc(&wqe->wq->worker_refs);
>   			create_io_worker(wqe->wq, wqe, acct->index, first);
> +		}
>   	}
>   }
>   
>