[dpdk-dev] [BUG] ixgbe vector cannot compile without bulk alloc

[Thomas Monjalon]

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=n
> > >   CONFIG_RTE_IXGBE_INC_VECTOR=y
> > > Building this config gives this error:
> > >   lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c:69:24:
> > >   error: ?struct igb_rx_queue? has no member named ?fake_mbuf?
> > > 
> > > I'd like a confirmation that it will be always incompatible.
> > > Thanks
> > 
> > Hi Thomas,
> > 
> > I don't think these options should always be incompatible, though as you 
> > point
> > out you do need to turn on bulk alloc support in order to use the vector 
> > PMD.
> > Why do you ask? There are no immediate plans to remove the dependency on 
> > our end.

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):

--- 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] = zeroed_desc;
        }

-#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        /*
         * initialize extra software ring entries. Space for these extra
         * entries is always allocated
         */
        memset(&rxq->fake_mbuf, 0x0, sizeof(rxq->fake_mbuf));
+#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST; ++i) {
                rxq->sw_ring[rxq->nb_rx_desc + i].mbuf = &rxq->fake_mbuf;
        }
--- 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 otherwise. */
        uint8_t             drop_en;  /**< If not 0, set SRRCTL.Drop_En. */
        uint8_t             rx_deferred_start; /**< not in global dev start. */
-#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        /** need to alloc dummy mbuf, for wraparound when scanning hw ring */
        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

> I think the compilation shouldn't fail without a proper message.
> In order to distinguish a real compilation error from an incompatibility,
> we should add a warning in the makefile.
> Ideally, the build system should handle dependencies. But waiting this ideal
> time, a warning would be graceful.

Do you agree that something like this would be OK?

--- a/lib/librte_pmd_ixgbe/Makefile
+++ b/lib/librte_pmd_ixgbe/Makefile
@@ -114,4 +114,8 @@ DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += lib/librte_eal 
lib/librte_ether
 DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += lib/librte_mempool lib/librte_mbuf
 DEPDIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += lib/librte_net lib/librte_malloc

+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

Thanks
-- 
Thomas