Re: [PATCH 2/3] virtio_console: fixup potential cpu stall when free unused bufs

Michael S. Tsirkin
2023-06-09T16:06:57Z

On Fri, Jun 09, 2023 at 09:18:16PM +0800, Xianting Tian wrote:
> Cpu stall issue may happen if device is configured with multi queues
> and large queue depth, so fix it.

"may happen" is ambigous.

So is this: "for virtio-net we were getting
stall on CPU was observed message, this driver is similar
so theoretically the same logic applies"

or is this

"the following error occured: ..... "

?

> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
> ---
> drivers/char/virtio_console.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index b65c809a4e97..5ec4cf4ea919 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -1935,6 +1935,7 @@ static void remove_vqs(struct ports_device *portdev)
> flush_bufs(vq, true);
> while ((buf = virtqueue_detach_unused_buf(vq)))
> free_buf(buf, true);
> + cond_resched();
> }
> portdev->vdev->config->del_vqs(portdev->vdev);
> kfree(portdev->in_vqs);
> --
> 2.17.1