On Fri, Jun 13, 2025 at 1:51 AM lirongqing <lirongq...@baidu.com> wrote:
>
> From: Li RongQing <lirongq...@baidu.com>
>
> Since clear_bit is an atomic operation, the spinlock is redundant and
> can be removed, reducing lock contention is good for performance.
>
> Signed-off-by: Li RongQing <lirongq...@baidu.com>
> ---
> fs/fuse/virtio_fs.c | 2 --
> 1 file changed, 2 deletions(-)
The spin lock originally protected req->list, so the lock has no use here.
The initial req->list access is still protected by fpq->lock in
virtio_fs_requests_done_work():
while ((req = virtqueue_get_buf(vq, &len)) != NULL) {
spin_lock(&fpq->lock);
list_move_tail(&req->list, &reqs);
spin_unlock(&fpq->lock);
}
Looks safe, but please see the kernel test robot email about an unused
variable warning.
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
>
> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> index 8f2e2f3..de34179 100644
> --- a/fs/fuse/virtio_fs.c
> +++ b/fs/fuse/virtio_fs.c
> @@ -791,9 +791,7 @@ static void virtio_fs_request_complete(struct fuse_req
> *req,
> }
> }
>
> - spin_lock(&fpq->lock);
> clear_bit(FR_SENT, &req->flags);
> - spin_unlock(&fpq->lock);
>
> fuse_request_end(req);
> spin_lock(&fsvq->lock);
> --
> 2.9.4
>
>
