Re: [dpdk-stable] [dpdk-dev] [PATCH] net/mlx5: fix file path location of HW counters

[Raslan Darawsheh <rasland@mellanox.com>]

Hi,

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Shy Shyman
> Sent: Wednesday, July 15, 2020 1:51 PM
> To: dev@dpdk.org
> Cc: Slava Ovsiienko <viacheslavo@mellanox.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] net/mlx5: fix file path location of HW counters
> 
> When debugging performance of a DPDK application the user may
> need to view the different statistics of DPDK(for example out_of_buffer)
> This can be enabled by using testpmd command 'show port xstats
> <port_id>' for example.
> 
> The current implementation assumes legacy mode in which the
> counters
> are at <ibdev_path>/<port_id>/hw_counters/<file_name>.
> In switchdev mode the counters file is located right after the device
> name, hence resides at <ibdev_path>/hw_counters.
> 
> The fix tries to open the path in the second location after a failure
> to open the file from the first location.
> 
> Fixes: 9c0a9eed37f1 ("net/mlx5: switch to the names in the shared IB
> context")
> 
> Cc: stable@dpdk.org
> Cc: viacheslavo@mellanox.com
> 
> Signed-off-by: Shy Shyman <shys@mellanox.com>
> ---
>  drivers/net/mlx5/linux/mlx5_os.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/mlx5/linux/mlx5_os.c
> b/drivers/net/mlx5/linux/mlx5_os.c
> index 2dc57b20ef..0edc96299c 100644
> --- a/drivers/net/mlx5/linux/mlx5_os.c
> +++ b/drivers/net/mlx5/linux/mlx5_os.c
> @@ -1948,10 +1948,20 @@ mlx5_os_read_dev_stat(struct mlx5_priv *priv,
> const char *ctr_name,
> 
>  	if (priv->sh) {
>  		MKSTR(path, "%s/ports/%d/hw_counters/%s",
> -			  priv->sh->ibdev_path,
> -			  priv->dev_port,
> -			  ctr_name);
> +		      priv->sh->ibdev_path,
> +		      priv->dev_port,
> +		      ctr_name);
>  		fd = open(path, O_RDONLY);
> +		/*
> +  		 * in switchdev the file location is not per port
> +		 * but rather in <ibdev_path>/hw_counters/<file_name>.
> +		*/
> +		if (fd == -1) {
> +			MKSTR(path1, "%s/hw_counters/%s",
> +			      priv->sh->ibdev_path,
> +			      ctr_name);
> +			fd = open(path1, O_RDONLY);
> +		}
>  		if (fd != -1) {
>  			char buf[21] = {'\0'};
>  			ssize_t n = read(fd, buf, sizeof(buf));
> --
> 2.21.0

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh