Re: [dpdk-dev] [PATCH v8 2/9] net/virtio: enable vectorized path

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 4/23/20 10:46 AM, Liu, Yong wrote:
> 
> 
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Sent: Thursday, April 23, 2020 4:34 PM
>> To: Liu, Yong <yong.liu@intel.com>; Ye, Xiaolong <xiaolong.ye@intel.com>;
>> Wang, Zhihong <zhihong.wang@intel.com>
>> Cc: Van Haaren, Harry <harry.van.haaren@intel.com>; dev@dpdk.org
>> Subject: Re: [PATCH v8 2/9] net/virtio: enable vectorized path
>>
>>
>>
>> On 4/23/20 2:30 PM, Marvin Liu wrote:
>>> Previously, virtio split ring vectorized path is enabled as default.
>>
>> s/is/was/
>> s/as/by/
>>
>>> This is not suitable for everyone because of that path not follow virtio
>>
>> s/because of that path not follow/because that path does not follow the/
>>
>>> spec. Add new config for virtio vectorized path selection. By default
>>> vectorized path is disabled.
>>
>> I think we can keep it enabled by default for consistency between make &
>> meson, now that you are providing a devarg for it that is disabled by
>> default.
>>
>> Maybe we can just drop this config flag, what do you think?
>>
> 
> Maxime, 
> Devarg will only have effect on virtio-user path selection, while DPDK configuration can affect both virtio pmd and virtio-user.
> It maybe worth to add new configuration as it can allow user to choice whether disabled vectorized path in virtio pmd. 

Ok, so we had a misunderstanding. I was requesting the the devarg to be
effective also for the Virtio PMD, disabled by default.

Thanks,
Maxime
> IMHO, AVX512 instructions should be selective in each component. 
> 
> Regards,
> Marvin
> 
>> Thanks,
>> Maxime
>>
>>> Signed-off-by: Marvin Liu <yong.liu@intel.com>
>>>
>>> diff --git a/config/common_base b/config/common_base
>>> index 00d8d0792..334a26a17 100644
>>> --- a/config/common_base
>>> +++ b/config/common_base
>>> @@ -456,6 +456,7 @@ CONFIG_RTE_LIBRTE_VIRTIO_PMD=y
>>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_RX=n
>>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_TX=n
>>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_DUMP=n
>>> +CONFIG_RTE_LIBRTE_VIRTIO_INC_VECTOR=n
>>>
>>>  #
>>>  # Compile virtio device emulation inside virtio PMD driver
>>> diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
>>> index c9edb84ee..4b69827ab 100644
>>> --- a/drivers/net/virtio/Makefile
>>> +++ b/drivers/net/virtio/Makefile
>>> @@ -28,6 +28,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) +=
>> virtio_rxtx.c
>>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_ethdev.c
>>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple.c
>>>
>>> +ifeq ($(CONFIG_RTE_LIBRTE_VIRTIO_INC_VECTOR),y)
>>>  ifeq ($(CONFIG_RTE_ARCH_X86),y)
>>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple_sse.c
>>>  else ifeq ($(CONFIG_RTE_ARCH_PPC_64),y)
>>> @@ -35,6 +36,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) +=
>> virtio_rxtx_simple_altivec.c
>>>  else ifneq ($(filter y,$(CONFIG_RTE_ARCH_ARM)
>> $(CONFIG_RTE_ARCH_ARM64)),)
>>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple_neon.c
>>>  endif
>>> +endif
>>>
>>>  ifeq ($(CONFIG_RTE_VIRTIO_USER),y)
>>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_user.c
>>> diff --git a/drivers/net/virtio/meson.build b/drivers/net/virtio/meson.build
>>> index 15150eea1..ce3525ef5 100644
>>> --- a/drivers/net/virtio/meson.build
>>> +++ b/drivers/net/virtio/meson.build
>>> @@ -8,6 +8,7 @@ sources += files('virtio_ethdev.c',
>>>  	'virtqueue.c')
>>>  deps += ['kvargs', 'bus_pci']
>>>
>>> +dpdk_conf.set('RTE_LIBRTE_VIRTIO_INC_VECTOR', 1)
>>>  if arch_subdir == 'x86'
>>>  	sources += files('virtio_rxtx_simple_sse.c')
>>>  elif arch_subdir == 'ppc'
>>>
>