# Re: \[PATCH\] vhost: reduce stack usage in log\_used

- From: Jason Wang \<hidden\>
- Date: 2020-09-15 07:54:21 
- List: netdev
- Page: https://ratatoskr.run/netdev/2020/09/6105200
- Thread: https://ratatoskr.run/kvm/2020/09/6102037/t.md

```text

On 2020/9/15 上午2:08, Li Wang wrote:
> Fix the warning: [-Werror=-Wframe-larger-than=]
>
> drivers/vhost/vhost.c: In function log_used:
> drivers/vhost/vhost.c:1906:1:
> warning: the frame size of 1040 bytes is larger than 1024 bytes
>
> Signed-off-by: Li Wang <redacted>
> ---
>   drivers/vhost/vhost.c | 2 +-
>   drivers/vhost/vhost.h | 1 +
>   2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index b45519c..31837a5
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1884,7 +1884,7 @@ static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len)
>   
>   static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len)
>   {
> -	struct iovec iov[64];
> +	struct iovec *iov = vq->log_iov;
>   	int i, ret;
>   
>   	if (!vq->iotlb)
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 9032d3c..5fe4b47
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -123,6 +123,7 @@ struct vhost_virtqueue {
>   	/* Log write descriptors */
>   	void __user *log_base;
>   	struct vhost_log *log;
> +	struct iovec log_iov[64];
>   
>   	/* Ring endianness. Defaults to legacy native endianness.
>   	 * Set to true when starting a modern virtio device. */


Acked-by: Jason Wang <redacted>


```