[PATCH net] xen/netback: Properly initialize credit_bytes

[PATCH net] xen/netback: Properly initialize credit_bytes

[Ross Lagerwall]

Commit e9ce7cb6b107 ("xen-netback: Factor queue-specific data into queue
struct") introduced a regression when moving queue-specific data into
the queue struct by failing to set the credit_bytes field. This
prevented bandwidth limiting from working. Initialize the field as it
was done before multiqueue support was added.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
---
 drivers/net/xen-netback/xenbus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 3d8dbf5..1be3ef3 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -793,7 +793,7 @@ static void connect(struct backend_info *be)
 			goto err;
 		}
 
-		queue->remaining_credit = credit_bytes;
+		queue->remaining_credit = queue->credit_bytes = credit_bytes;
 		queue->credit_usec = credit_usec;
 
 		err = connect_rings(be, queue);
-- 
2.1.0

Re: [PATCH net] xen/netback: Properly initialize credit_bytes

[Sergei Shtylyov]

Hello.

On 05/11/2015 08:04 PM, Ross Lagerwall wrote:

> Commit e9ce7cb6b107 ("xen-netback: Factor queue-specific data into queue
> struct") introduced a regression when moving queue-specific data into
> the queue struct by failing to set the credit_bytes field. This
> prevented bandwidth limiting from working. Initialize the field as it
> was done before multiqueue support was added.

> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
> Acked-by: Wei Liu <wei.liu2@citrix.com>
> ---
>   drivers/net/xen-netback/xenbus.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

> diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
> index 3d8dbf5..1be3ef3 100644
> --- a/drivers/net/xen-netback/xenbus.c
> +++ b/drivers/net/xen-netback/xenbus.c
> @@ -793,7 +793,7 @@ static void connect(struct backend_info *be)
>   			goto err;
>   		}
>
> -		queue->remaining_credit = credit_bytes;
> +		queue->remaining_credit = queue->credit_bytes = credit_bytes;

[headless@wasted linux]$ scripts/checkpatch.pl 
~/patches/xen_netback-Properly-initialize-credit_bytes.patch
CHECK: multiple assignments should be avoided
#22: FILE: drivers/net/xen-netback/xenbus.c:796:
+		queue->remaining_credit = queue->credit_bytes = credit_bytes;

total: 0 errors, 0 warnings, 1 checks, 8 lines checked

/home/headless/patches/xen_netback-Properly-initialize-credit_bytes.patch has 
style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

WBR, Sergei