From: fengchengwen <fengchengwen@huawei.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
"thomas@monjalon.net" <thomas@monjalon.net>,
Bruce Richardson <bruce.richardson@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"jerinj@marvell.com" <jerinj@marvell.com>,
Ruifeng Wang <Ruifeng.Wang@arm.com>,
"viktorin@rehivetech.com" <viktorin@rehivetech.com>,
"jerinjacobk@gmail.com" <jerinjacobk@gmail.com>,
"juraj.linkes@pantheon.tech" <juraj.linkes@pantheon.tech>,
nd <nd@arm.com>
Subject: Re: [dpdk-dev] [PATCH v5 2/2] net/hns3: refactor SVE code compile method
Date: Wed, 19 May 2021 08:18:26 +0800 [thread overview]
Message-ID: <8765778c-c891-1039-c15e-8a4039e7950a@huawei.com> (raw)
In-Reply-To: <cb2e1ba4-ef52-0e76-6f0e-f3ddd308b1da@intel.com>
On 2021/5/19 0:37, Ferruh Yigit wrote:
> On 5/18/2021 5:12 PM, Honnappa Nagarahalli wrote:
>>>> <snip>
>>>>>
>>>>> On 5/14/2021 10:53 AM, Chengwen Feng wrote:
>>>>>> Currently, the SVE code is compiled only when -march supports SVE
>>>>>> (e.g. '-march=armv8.2a+sve'), there maybe some problem[1] with this
>>>>>> approach.
>>>>>>
>>>>>> The solution:
>>>>>> a. If the minimum instruction set support SVE then compiles it.
>>>>>> b. Else if the compiler support SVE then compiles it.
>>>>>> c. Otherwise don't compile it.
>>>>>>
>>>>>> [1] https://mails.dpdk.org/archives/dev/2021-April/208189.html
>>>>>>
>>>>>
>>>>> Hi Chengwen,
>>>>>
>>>>> As far as I understand from above problem statement, you want to
>>>>> produce a binary that can run in two different platforms, one
>>>>> supports only NEON instructions, other supports NEON + SVE.
>>>>>
>>>>> For this driver should be compiled in a way to support min
>>>>> instruction set, which is NEON.
>>>>>
>>>>> There are two build items,
>>>>>
>>>>> 1) hns3_rxtx_vec_sve.c
>>>>> 2) rest of the library
>>>>>
>>>>> There is already runtime checks to select Rx/Tx functions, so it is
>>>>> safe to build
>>>>> (1) as long as compiler supports. If the platform doesn't support
>>>>> SVE, the SVE path won't be selected during runtime.
>>>>>
>>>>> For (2), it should be build to support NEON only, if it is compiled
>>>>> to support SVE, it won't run on the platform that only supports NEON.
>>>>>
>>>>> So, in below, if '__ARM_FEATURE_SVE' is supported, all driver is
>>>>> build with SVE support, won't this cause a problem on the NEON platform?
>>>> The first if statement checks if the user has enabled SVE during compilation
>>> which indicates that the user will run the binary on a platform that has SVE
>>> (the minimum ISA level supported by this binary), hence it is ok to compile all
>>> the code with SVE.
>>>>
>>>
>>> So it is related to the what user provided (I assume as compiler flag), instead
>>> of host HW capability.
>> It is the HW host capability as provided in the compiler flag. It is coming from config/arm/meson.build.
>>
>
> Is this patch has dependency to 1/2, that updates 'config/arm/meson.build'?
>
> What I understand is, if user provides compiler argument to request SVE,
> something like '-march=armv8.2-a+sve', and host HW supports it, whole driver
> will be built with SVE support.
>
> If user not request SVE, driver won't be compiled with SVE support even if HW
> support it, but only 'hns3_rxtx_vec_sve.c' will be compiled if compiler supports
> SVE.
>
> Is above correct and does it have any dependency to first patch, I thought this
> is independent from first patch.
>
Yes, you are right, it's independent from first patch.
>
>>>
>>>> If the user has not enabled SVE during compilation which indicates the user
>>> might run the binary on a platform that does not have SVE, the second if
>>> statement, checks if the compiler supports SVE. If yes, it will compile the SVE
>>> version of the driver as well and the run time checks choose the correct
>>> version.
>>>>
>>>
>>> OK, this sounds good, thanks for clarification.
>>>
>>>>>
>>>>> What do you think to only keep the else leg of the below check, which
>>>>> is if compiler supports SVE, set '-DCC_SVE_SUPPORT' flag and only
>>>>> build (1) with SVE flag?
>>>>>
>>>>>> Fixes: 8c25b02b082a ("net/hns3: fix enabling SVE Rx/Tx")
>>>>>> Fixes: 952ebacce4f2 ("net/hns3: support SVE Rx")
>>>>>> Cc: stable@dpdk.org
>>>>>>
>>>>>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
>>>>>> ---
>>>>>> drivers/net/hns3/hns3_rxtx.c | 2 +- drivers/net/hns3/meson.build
>>>>>> | 13 +++++++++++++
>>>>>> 2 files changed, 14 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/drivers/net/hns3/hns3_rxtx.c
>>>>>> b/drivers/net/hns3/hns3_rxtx.c index 1d7a769..4ef20c6 100644
>>>>>> --- a/drivers/net/hns3/hns3_rxtx.c
>>>>>> +++ b/drivers/net/hns3/hns3_rxtx.c
>>>>>> @@ -2808,7 +2808,7 @@ hns3_get_default_vec_support(void)
>>>>>> static bool
>>>>>> hns3_get_sve_support(void)
>>>>>> {
>>>>>> -#if defined(RTE_ARCH_ARM64) && defined(__ARM_FEATURE_SVE)
>>>>>> +#if defined(CC_SVE_SUPPORT)
>>>>>> if (rte_vect_get_max_simd_bitwidth() < RTE_VECT_SIMD_256)
>>>>>> return false;
>>>>>> if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SVE))
>>>>>> diff --git a/drivers/net/hns3/meson.build
>>>>>> b/drivers/net/hns3/meson.build index 53c7df7..8563d70 100644
>>>>>> --- a/drivers/net/hns3/meson.build
>>>>>> +++ b/drivers/net/hns3/meson.build
>>>>>> @@ -35,7 +35,20 @@ deps += ['hash']
>>>>>>
>>>>>> if arch_subdir == 'arm' and dpdk_conf.get('RTE_ARCH_64')
>>>>>> sources += files('hns3_rxtx_vec.c')
>>>>>> +
>>>>>> + # compile SVE when:
>>>>>> + # a. support SVE in minimum instruction set baseline
>>>>>> + # b. it's not minimum instruction set, but compiler support
>>>>>> if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != ''
>>>>>> + cflags += ['-DCC_SVE_SUPPORT']
>>>>>> sources += files('hns3_rxtx_vec_sve.c')
>>>>>> + elif cc.has_argument('-march=armv8.2-a+sve')
>>>>>> + cflags += ['-DCC_SVE_SUPPORT']
>>>>>> + hns3_sve_lib = static_library('hns3_sve_lib',
>>>>>> + 'hns3_rxtx_vec_sve.c',
>>>>>> + dependencies: [static_rte_ethdev],
>>>>>> + include_directories: includes,
>>>>>> + c_args: [cflags, '-march=armv8.2-a+sve'])
>>>>>> + objs += hns3_sve_lib.extract_objects('hns3_rxtx_vec_sve.c')
>>>>>> endif
>>>>>> endif
>>>>>>
>>>>
>>
>
>
> .
>
next prev parent reply other threads:[~2021-05-19 0:18 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-12 8:28 [dpdk-dev] [PATCH 0/2] bugfix for Kunpeng930 SVE compile Chengwen Feng
2021-05-12 8:28 ` [dpdk-dev] [PATCH 1/2] config/arm: add non-SVE march for soc kunpeng930 Chengwen Feng
2021-05-12 8:44 ` Jerin Jacob
2021-05-12 23:00 ` Honnappa Nagarahalli
2021-05-13 4:49 ` fengchengwen
2021-05-12 8:28 ` [dpdk-dev] [PATCH 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-12 23:12 ` Honnappa Nagarahalli
2021-05-12 23:21 ` Honnappa Nagarahalli
2021-05-13 0:51 ` fengchengwen
2021-05-13 20:42 ` Honnappa Nagarahalli
2021-05-13 10:04 ` Bruce Richardson
2021-05-13 4:41 ` [dpdk-dev] [PATCH v2 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-13 4:41 ` [dpdk-dev] [PATCH v2 1/2] config/arm: select best -march parameter for kunpeng soc Chengwen Feng
2021-05-13 4:41 ` [dpdk-dev] [PATCH v2 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-13 6:16 ` [dpdk-dev] [PATCH v3 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-13 6:16 ` [dpdk-dev] [PATCH v3 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-05-13 6:16 ` [dpdk-dev] [PATCH v3 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-13 13:08 ` [dpdk-dev] [PATCH v4 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-13 13:08 ` [dpdk-dev] [PATCH v4 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-05-13 15:24 ` Jerin Jacob
2021-05-13 23:12 ` Honnappa Nagarahalli
2021-05-14 10:23 ` fengchengwen
2021-05-18 13:25 ` Honnappa Nagarahalli
2021-05-18 13:45 ` Jerin Jacob
2021-05-13 13:08 ` [dpdk-dev] [PATCH v4 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-13 22:19 ` Honnappa Nagarahalli
2021-05-14 2:53 ` fengchengwen
2021-05-14 9:53 ` [dpdk-dev] [PATCH v5 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-14 9:53 ` [dpdk-dev] [PATCH v5 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-05-14 9:53 ` [dpdk-dev] [PATCH v5 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-14 14:12 ` Honnappa Nagarahalli
2021-05-18 12:41 ` fengchengwen
2021-05-18 13:11 ` Honnappa Nagarahalli
2021-05-18 13:12 ` Honnappa Nagarahalli
2021-05-18 13:24 ` Ferruh Yigit
2021-05-18 16:27 ` Ferruh Yigit
2021-05-19 0:23 ` fengchengwen
2021-05-19 8:08 ` David Marchand
2021-05-19 9:27 ` Ferruh Yigit
2021-05-19 12:16 ` fengchengwen
2021-05-19 12:37 ` David Marchand
2021-05-19 13:35 ` fengchengwen
2021-05-18 14:40 ` Ferruh Yigit
2021-05-18 15:15 ` Bruce Richardson
2021-05-18 16:12 ` Ferruh Yigit
2021-05-18 15:48 ` Honnappa Nagarahalli
2021-05-18 16:00 ` Ferruh Yigit
2021-05-18 16:12 ` Honnappa Nagarahalli
2021-05-18 16:37 ` Ferruh Yigit
2021-05-19 0:18 ` fengchengwen [this message]
2021-05-19 13:25 ` [dpdk-dev] [PATCH v6 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-19 13:25 ` [dpdk-dev] [PATCH v6 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-05-19 14:05 ` Jerin Jacob
2021-05-20 22:38 ` Honnappa Nagarahalli
2021-05-19 13:25 ` [dpdk-dev] [PATCH v6 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-19 15:02 ` Ferruh Yigit
2021-05-20 1:11 ` fengchengwen
2021-05-20 7:57 ` Ferruh Yigit
2021-05-20 8:24 ` Ruifeng Wang
2021-05-20 10:55 ` fengchengwen
2021-05-21 5:21 ` Ruifeng Wang
2021-05-21 6:53 ` fengchengwen
2021-05-24 5:38 ` Ruifeng Wang
2021-05-24 8:43 ` fengchengwen
2021-05-24 10:03 ` Ruifeng Wang
2021-05-24 13:15 ` fengchengwen
2021-05-24 13:12 ` [dpdk-dev] [PATCH v7 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-24 13:12 ` [dpdk-dev] [PATCH v7 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-05-24 13:12 ` [dpdk-dev] [PATCH v7 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-24 13:23 ` [dpdk-dev] [PATCH v8 0/2] bugfix for Kunpeng SVE compile Chengwen Feng
2021-05-24 13:23 ` [dpdk-dev] [PATCH v8 1/2] config/arm: select most suitable -march for kunpeng soc Chengwen Feng
2021-06-17 7:03 ` Thomas Monjalon
2021-06-17 23:33 ` Honnappa Nagarahalli
2021-06-21 0:52 ` fengchengwen
2021-06-23 8:08 ` Thomas Monjalon
2021-06-23 8:24 ` fengchengwen
2021-05-24 13:23 ` [dpdk-dev] [PATCH v8 2/2] net/hns3: refactor SVE code compile method Chengwen Feng
2021-05-25 6:04 ` Ruifeng Wang
2021-05-27 7:07 ` Fengchengwen
2021-06-12 7:09 ` fengchengwen
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