From: "Qiu, Michael" <michael.qiu@intel.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v1] virtio: Use cpuflag for vector api
Date: Fri, 4 Mar 2016 06:36:40 +0000 [thread overview]
Message-ID: <533710CFB86FA344BFBF2D6802E6028622F5D307@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <20160302024918.GQ14300@yliu-dev.sh.intel.com>
On 3/2/2016 10:48 AM, Yuanhan Liu wrote:
> On Wed, Mar 02, 2016 at 02:10:14AM +0000, Qiu, Michael wrote:
>> On 3/1/2016 5:46 PM, Santosh Shukla wrote:
>>> On Tue, Mar 1, 2016 at 2:41 PM, Qiu, Michael <michael.qiu@intel.com> wrote:
>>>> On 2/26/2016 4:53 PM, 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
>>>>>
>>>>> todo:
>>>>> 1) Move virtio_recv_pkts_vec() implementation to
>>>>> drivers/virtio/virtio_vec_<arch>.h file.
>>>>> 2) Remove use_simple_rxtx flag, so that virtio/virtio_vec_<arch>.h
>>>>> files to provide vectored/non-vectored rx/tx apis.
>>>>>
>>>>> Signed-off-by: Santosh Shukla <sshukla@mvista.com>
>>>>> ---
>>>>> - v1: This is a rework of patch [1].
>>>>> Note: This patch will let non-x86 arch to use virtio pmd.
>>>>>
>>>>> [1] http://dpdk.org/dev/patchwork/patch/10429/
>>>>>
>>>>> drivers/net/virtio/virtio_rxtx.c | 16 +++++++++++++++-
>>>>> drivers/net/virtio/virtio_rxtx.h | 2 ++
>>>>> drivers/net/virtio/virtio_rxtx_simple.c | 11 ++++++++++-
>>>>> 3 files changed, 27 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>>>>> index 41a1366..ec0b8de 100644
>>>>> --- a/drivers/net/virtio/virtio_rxtx.c
>>>>> +++ b/drivers/net/virtio/virtio_rxtx.c
>>>>> @@ -67,7 +67,9 @@
>>>>> #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
>>>>> ETH_TXQ_FLAGS_NOOFFLOADS)
>>>>>
>>>>> +#ifdef RTE_MACHINE_CPUFLAG_SSSE3
>>>>> static int use_simple_rxtx;
>>>>> +#endif
>>>>>
>>>>>
>>>> I don't think so much #ifdef ... #endif in *.c file is a good choice.
>>>> Would you consider let it only in header file like:
>>>>
>>>> in drivers/net/virtio/virtio_rxtx.h
>>>>
>>>> [...]
>>>>
>>>> #ifdef RTE_MACHINE_CPUFLAG_SSSE3
>>>> int virtio_rxq_vec_setup(struct virtqueue *rxq);
>>>>
>>>> int virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
>>>> struct rte_mbuf *m);
>>>> #else
>>>> int virtio_rxq_vec_setup(__rte_unused struct virtqueue *rxq) {return -1;}
>>>> int virtqueue_enqueue_recv_refill_simple(__rte_unused struct virtqueue *vq,
>>>> __rte_unused struct rte_mbuf *m) {
>>>> return -1;
>>>> }
>>>> #endif
>>>>
>>>> and remove most #ifdef ... #endif in *.c file.
>>>>
>>> I guess, above approach wont work for non-x86 arch, ad those func are
>>> dummy, right? also code wont build for arm/non-86 arch because
>>> tx/rx_pkt_burst callback will be using x86 specific virtio vec rx/tx
>>> api.
>> You may right, but you really need to reduce the #ifdef in *.c files.
> In general, yes. But for this case, no: those vec stuff are for
> platforms that support it. For other platforms, we should not
> invoke a dummy function like virtio_rxq_vec_setup() at all.
>
> The right way to go is to add another wrapper beyond the vector
> stuff, something like:
>
> virtio_rxq_setup()
> {
>
> if (has_vec_support)
> virtio_rxq_vec_setup();
> else
> virtio_rxq_generic_setup();
> }
Actually, we could call vec first and if set up failed, fall back to
simple mode. Thus we could use dummy func, and it could make lift simple.
Thanks,
Michael
> Where virtio_rxq_vec_setup() could have a per-arch implementation,
> say for X86, or ARM.
>
> It touchs more code, but for now, I'd like to make it simple first.
> With the virtio_rxtx_simple.c isolated from Makefile, there aren't
> many #ifdef after all.
>
> --yliu
>
prev parent reply other threads:[~2016-03-04 6:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 8:51 Santosh Shukla
2016-02-29 4:27 ` Yuanhan Liu
2016-02-29 5:33 ` Xie, Huawei
2016-02-29 12:31 ` Santosh Shukla
2016-03-01 5:55 ` Yuanhan Liu
2016-03-01 6:10 ` Santosh Shukla
2016-03-01 6:22 ` Yuanhan Liu
2016-02-29 12:58 ` [dpdk-dev] [PATCH v2] " Santosh Shukla
2016-03-01 5:59 ` Yuanhan Liu
2016-03-01 6:08 ` Santosh Shukla
2016-03-01 6:32 ` Yuanhan Liu
2016-03-01 10:07 ` Santosh Shukla
2016-03-01 10:02 ` [dpdk-dev] [PATCH v1 0/3] virtio vector and misc Santosh Shukla
2016-03-01 10:02 ` [dpdk-dev] [PATCH v1 1/3] virtio: use vector rx/tx for ssse cpuflag only Santosh Shukla
2016-03-01 10:02 ` [dpdk-dev] [PATCH v1 2/3] config: enable virtio for armv7/v8 Santosh Shukla
2016-03-01 10:02 ` [dpdk-dev] [PATCH v1 3/3] guide/release: add virtio for arm feature info Santosh Shukla
2016-03-02 8:32 ` [dpdk-dev] [PATCH v1 0/3] virtio vector and misc Yuanhan Liu
2016-03-02 8:41 ` Santosh Shukla
2016-03-03 13:26 ` Thomas Monjalon
2016-03-03 13:50 ` Santosh Shukla
2016-03-01 9:11 ` [dpdk-dev] [PATCH v1] virtio: Use cpuflag for vector api Qiu, Michael
2016-03-01 9:45 ` Santosh Shukla
2016-03-02 2:10 ` Qiu, Michael
2016-03-02 2:49 ` Yuanhan Liu
2016-03-04 6:36 ` Qiu, Michael [this message]
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