[dpdk-dev] [PATCH v1] [net/tap] add logic to assign speed from user

Wiles, Keith keith.wiles at intel.com
Thu Dec 21 14:38:25 CET 2017



> On Dec 21, 2017, at 10:53 AM, Vipin Varghese <vipin.varghese at intel.com> wrote:
> 
> TAP speed is passed as user argument, but never set to interface.
> New logic brings speed get and set to LOCAL and REMOTE interfaces.
> 
> Updated the default PMD speeed to 10M as per Linux Kernel default
> value.

The problem in setting the link speed to 10M is that TAP will not limit its traffic to 10M. Applications like pktgen and others use the Link speed to calculate the bit rate, which will be broken now.

I would suggest making the default value 10G or 40G instead as CPU speeds will continue to increase. Forcing someone to always add the link speed seems a bit much when we know the systems can send/receive much higher then 10M, which is the reason 10G was picked. Please set the default back to 10G or some much higher number.

> 
> Signed-off-by: Vipin Varghese <vipin.varghese at intel.com>
> ---
> drivers/net/tap/rte_eth_tap.c | 185 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 182 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index 6b27679..7238504 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -62,6 +62,8 @@
> #include <linux/if_ether.h>
> #include <linux/version.h>
> #include <fcntl.h>
> +#include <linux/ethtool.h>
> +#include <linux/sockios.h>
> 

Regards,
Keith



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