From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Subject: Re: [BUG] ixgbe vector cannot compile without bulk alloc
Date: Thu, 29 Jan 2015 16:27:49 -0700
Message-ID: <20150129232748.GA11276@bricha3-MOBL3>
References: <5418900.qsIIdEyxOF@xps13> <20141201171854.GH4856@bricha3-MOBL3>
 <1953153.vMxMoL6Atb@xps13> <9179246.fLSLRuqZit@xps13>
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To: Thomas Monjalon <thomas.monjalon-pdR9zngts4EAvxtiuMwx3w@public.gmane.org>
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On Thu, Jan 29, 2015 at 11:18:01PM +0100, Thomas Monjalon wrote:
> 2014-12-01 18:22, Thomas Monjalon:
> > 2014-12-01 17:18, Bruce Richardson:
> > > On Mon, Dec 01, 2014 at 06:10:18PM +0100, Thomas Monjalon wrote:
> > > > These 2 configuration options are incompatible:
> > > > 	CONFIG_RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC=3Dn
> > > > 	CONFIG_RTE_IXGBE_INC_VECTOR=3Dy
> > > > Building this config gives this error:
> > > > 	lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c:69:24:
> > > > 	error: =E2=80=98struct igb_rx_queue=E2=80=99 has no member named=
 =E2=80=98fake_mbuf=E2=80=99
> > > >=20
> > > > I'd like a confirmation that it will be always incompatible.
> > > > Thanks
> > >=20
> > > Hi Thomas,
> > >=20
> > > I don't think these options should always be incompatible, though a=
s you point
> > > out you do need to turn on bulk alloc support in order to use the v=
ector PMD.
> > > Why do you ask? There are no immediate plans to remove the dependen=
cy on our end.
>=20
> So you confirm that the ixgbe vpmd really needs Rx bulk alloc and this =
kind of
> patch cannot work at all (I don't know the design of vpmd):
>=20
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> @@ -2119,12 +2119,12 @@ ixgbe_reset_rx_queue(struct igb_rx_queue *rxq)
>                 rxq->rx_ring[i] =3D zeroed_desc;
>         }
> =20
> -#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
>         /*
>          * initialize extra software ring entries. Space for these extr=
a
>          * entries is always allocated
>          */
>         memset(&rxq->fake_mbuf, 0x0, sizeof(rxq->fake_mbuf));
> +#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
>         for (i =3D 0; i < RTE_PMD_IXGBE_RX_MAX_BURST; ++i) {
>                 rxq->sw_ring[rxq->nb_rx_desc + i].mbuf =3D &rxq->fake_m=
buf;
>         }
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> @@ -127,9 +127,9 @@ struct igb_rx_queue {
>         uint8_t             crc_len;  /**< 0 if CRC stripped, 4 otherwi=
se. */
>         uint8_t             drop_en;  /**< If not 0, set SRRCTL.Drop_En=
. */
>         uint8_t             rx_deferred_start; /**< not in global dev s=
tart. */
> -#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
>         /** need to alloc dummy mbuf, for wraparound when scanning hw r=
ing */
>         struct rte_mbuf fake_mbuf;
> +#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
>         /** hold packets to return to application */
>         struct rte_mbuf *rx_stage[RTE_PMD_IXGBE_RX_MAX_BURST*2];
>  #endif
>=20
> > I think the compilation shouldn't fail without a proper message.
> > In order to distinguish a real compilation error from an incompatibil=
ity,
> > we should add a warning in the makefile.
> > Ideally, the build system should handle dependencies. But waiting thi=
s ideal
> > time, a warning would be graceful.
>=20
> Do you agree that something like this would be OK?
>=20
> --- a/lib/librte_pmd_ixgbe/Makefile
> +++ b/lib/librte_pmd_ixgbe/Makefile
> @@ -114,4 +114,8 @@ DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) +=3D lib/lib=
rte_eal lib/librte_ether
>  DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) +=3D lib/librte_mempool lib/lib=
rte_mbuf
>  DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) +=3D lib/librte_net lib/librte_=
malloc
> =20
> +ifeq ($(CONFIG_RTE_IXGBE_INC_VECTOR)$(CONFIG_RTE_LIBRTE_IXGBE_RX_ALLOW=
_BULK_ALLOC),yn)
> +$(error The ixgbe vpmd depends on Rx bulk alloc)
> +endif
> +
>  include $(RTE_SDK)/mk/rte.lib.mk
>=20

Something like the above looks like a good solution to me.

/Bruce

> Thanks
> --=20
> Thomas