Re: [dpdk-dev] [PATCH v1] virtio: Use cpuflag for vector api

[Santosh Shukla <sshukla@mvista.com>]

On Mon, Feb 29, 2016 at 9:57 AM, Yuanhan Liu
<yuanhan.liu@linux.intel.com> wrote:
> On Fri, Feb 26, 2016 at 02:21:02PM +0530, Santosh Shukla wrote:
>> Check cpuflag macro before using vectored api.
>> -virtio_recv_pkts_vec() uses _sse3__ simd instruction for now so added cpuflag.
>> - Also wrap other vectored freind api ie..
>> 1) virtqueue_enqueue_recv_refill_simple
>> 2) virtio_rxq_vec_setup
>>
> ...
>> diff --git a/drivers/net/virtio/virtio_rxtx_simple.c b/drivers/net/virtio/virtio_rxtx_simple.c
>> index 3a1de9d..be51d7c 100644
>> --- a/drivers/net/virtio/virtio_rxtx_simple.c
>> +++ b/drivers/net/virtio/virtio_rxtx_simple.c
>
> Hmm, why not wrapping the whole file, instead of just few functions?
>

Better to refactor code and make arch specific. Current implementation
is temporary.
> Or maybe better, do a compile time check at the Makefile, something
> like:
>
>     if has_CPUFLAG_xxx
>         SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple.c
>     endif
>
Tried this approach but end up with link error,  If I try to fix below
link error then I will be ending up writing similar code,
linker error snap:

/work/santosh/thunder/nfs/dpdk/arm64-thunderx-linuxapp-gcc/lib/librte_pmd_virtio.a(virtio_rxtx.o):
In function `virtio_dev_rxtx_start':
virtio_rxtx.c:(.text+0x168c): undefined reference to
`virtqueue_enqueue_recv_refill_simple'
/work/santosh/thunder/nfs/dpdk/arm64-thunderx-linuxapp-gcc/lib/librte_pmd_virtio.a(virtio_rxtx.o):
In function `virtio_dev_rx_queue_setup':
virtio_rxtx.c:(.text+0x2364): undefined reference to `virtio_rxq_vec_setup'
/work/santosh/thunder/nfs/dpdk/arm64-thunderx-linuxapp-gcc/lib/librte_pmd_virtio.a(virtio_rxtx.o):
In function `virtio_dev_tx_queue_setup':
virtio_rxtx.c:(.text+0x2460): undefined reference to `virtio_xmit_pkts_simple'
virtio_rxtx.c:(.text+0x2464): undefined reference to `virtio_recv_pkts_vec'
virtio_rxtx.c:(.text+0x2468): undefined reference to `virtio_xmit_pkts_simple'
virtio_rxtx.c:(.text+0x246c): undefined reference to `virtio_recv_pkts_vec'
collect2: error: ld returned 1 exit status
make[5]: *** [test] Error 1
make[4]: *** [test] Error 2
make[3]: *** [app] Error 2

>
>         --yliu