Re: "TX WTHRESH must be set to 0 if tx_rs_thresh is greater than 1"

[Marc Sune <marc.sune-kpkqNMk1I7M@public.gmane.org>]

Which DPDK version are you using

marc

On 19/10/14 00:50, Matthew Hall wrote:
> Hello,
>
> I'm just trying to understand what you're supposed to do about this error to
> get the optiomal configuration / performance. The error message and comments
> seem like they're designed for Intel ethernet driver hackers not security
> hackers like myself! ;-)
>
> Note: I'm trying out the Intel 82545EM in VirtualBox because the virtio-net
> approach didn't work, for reasons I enumerated in some previous mails.
>
>      /*
>       * If rs_bit_thresh is greater than 1, then TX WTHRESH should be
>       * set to 0. If WTHRESH is greater than zero, the RS bit is ignored
>       * by the NIC and all descriptors are written back after the NIC
>       * accumulates WTHRESH descriptors.
>       */
>      if (tx_conf->tx_thresh.wthresh != 0 && tx_rs_thresh != 1) {
>          RTE_LOG(ERR, PMD, "TX WTHRESH must be set to 0 if "
>              "tx_rs_thresh is greater than 1. (tx_rs_thresh=%u "
>              "port=%d queue=%d)\n", (unsigned int)tx_rs_thresh,
>                  (int)dev->data->port_id, (int)queue_idx);
>          return -(EINVAL);
>      }
>
> Thanks,
> Matthew.