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From: Matthew Hall <mhall@mhcomputing.net>
To: dev@dpdk.org
Subject: [dpdk-dev] "TX WTHRESH must be set to 0 if tx_rs_thresh is greater than 1"
Date: Sat, 18 Oct 2014 15:50:02 -0700	[thread overview]
Message-ID: <20141018225002.GA17115@mhcomputing.net> (raw)


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);


             reply	other threads:[~2014-10-18 22:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-18 22:50 Matthew Hall [this message]
2014-10-19 13:46 ` Marc Sune
2014-10-19 17:08   ` Matthew Hall
2014-10-20  9:36     ` Bruce Richardson
2014-10-20 20:29       ` Matthew Hall

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