From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: Unit for tx_rate in rte_eth_set_queue_rate_limit?
Date: Tue, 20 Oct 2015 14:38:54 +0200
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To: Simon =?ISO-8859-1?Q?K=E5gstr=F6m?= <simon.kagstrom@netinsight.net>
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2015-10-20 14:20, Simon K=E5gstr=F6m:
> Hi!
>=20
> What is the unit of the tx_rate parameter to the
> rte_eth_set_queue_rate_limit function? It's documented as
>=20
> /**
>  * Set the rate limitation for a queue on an Ethernet device.
>  *
>  * @param port_id
>  *   The port identifier of the Ethernet device.
>  * @param queue_idx
>  *   The queue id.
>  * @param tx_rate
>  *   The tx rate allocated from the total link speed for this queue.
>  * @return
>  *   - (0) if successful.
>  *   - (-ENOTSUP) if hardware doesn't support this feature.
>  *   - (-ENODEV) if *port_id* invalid.
>  *   - (-EINVAL) if bad parameter.
>  */
> int rte_eth_set_queue_rate_limit(uint8_t port_id, uint16_t queue_idx,=

> =09=09=09uint16_t tx_rate);
>=20
> I parse this as meaning a percentage of total link speed, i.e., on a =
10
> Gbps link, 50 would mean 5Gbps, 10 means 1Gbps etc. Is this correct?

It's implemented only in ixgbe:
        /* Calculate the rate factor values to set */
        rf_int =3D (uint32_t)link_speed / (uint32_t)tx_rate;
        rf_dec =3D (uint32_t)link_speed % (uint32_t)tx_rate;
        rf_dec =3D (rf_dec << IXGBE_RTTBCNRC_RF_INT_SHIFT) / tx_rate;

        bcnrc_val =3D IXGBE_RTTBCNRC_RS_ENA;
        bcnrc_val |=3D ((rf_int << IXGBE_RTTBCNRC_RF_INT_SHIFT) &
                IXGBE_RTTBCNRC_RF_INT_MASK_M);
        bcnrc_val |=3D (rf_dec & IXGBE_RTTBCNRC_RF_DEC_MASK);

So you just need to check the datasheet and send a patch to make it cle=
ar :)
Thanks