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

[Santosh Shukla <sshukla@mvista.com>]

On Tue, Mar 1, 2016 at 11:25 AM, Yuanhan Liu
<yuanhan.liu@linux.intel.com> wrote:
> On Mon, Feb 29, 2016 at 06:01:38PM +0530, Santosh Shukla wrote:
>> 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.
>
> I'm okay to refactor, if it's a clean one. But moving virtio __driver__
> stuff to EAL, sorry, it still doesn't make too much sense to me.
>

You misunderstood my comment, my arch specific meaning
driver/net/virtio/virtio_vec_<arch>.h

> For this case, let's make it simple so far, and consider it when we
> have another vec implementation, or better refactor comes out.
>
>> > 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,
>
> Sure you need the first part of your patch. Yes, it's similar code,
> but it has fewer "#ifdef " conditions, and more importantly, it
> leaves virtio_rxtx_simple.c alone.
>

Ok.,
>         --yliu
>
>> 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'