Re: [dpdk-dev] "TX WTHRESH must be set to 0 if tx_rs_thresh is greater than 1"

[Matthew Hall <mhall@mhcomputing.net>]

1.7.1 with a few minor clang compatibility patches in the example apps
-- 
Sent from my mobile device.

On October 19, 2014 6:46:27 AM PDT, Marc Sune <marc.sune@bisdn.de> wrote:
>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.