[yocto] [meta-dpdk][PATCH] dpdk: Fix do_compile failure for qemux86 and qemux86-64

[He Zhe]

On 6/11/19 2:31 PM, Mittal, Anuj wrote:
> On Tue, 2019-06-11 at 11:06 +0800, zhe.he at windriver.com wrote:
>> From: He Zhe <zhe.he at windriver.com>
>>
>> DPDK_TARGET_MACHINE in bbappend in other layers forms the dpdk-
>> internal variable
>> MACHINE_CFLAGS which is passed to dpdk compilation command line
>> containing the
>> first -march parameter. And EXTRA_CFLAGS in dpdk.inc is passed to
>> dpdk command
>> line containing the second -march parameter. By mistake, the first
>> -march had
>> always overwritten the second one until the following commit of GCC
>> v9.1.0
>> 8c0f695d83d1 ("driver: Also prune joined switches with negation").
>>
>> Since it was fixed, the second -march, which was core2 for qemux86-64 
>> or
>> core2-32 for qemux86, began to take effect. But core2* does not have
>> SSE4.2
>> feature which is required by some dpdk instruction optimization and
>> thus cause
>> the following compilation failure.
>>
>> 9.1.0/include/smmintrin.h:179:1: error: inlining failed in call to
>> always_inline
>> '_mm_blendv_epi8': target specific option mismatch
>>   179 | _mm_blendv_epi8 (__m128i __X, __m128i __Y, __m128i __M)
>>       | ^~~~~~~~~~~~~~~
>>
>> This patch adds DPDK_EXTRA_CFLAGS to append appropriate -march,
>> corei7 which is
>> minimum and clear and independent of host machine, to dpdk
>> compilation command
>> line to overwrite all previous ones, without having to change dpdk
>> source code.
>>
>> Note that as we do not want to change the default tune core2* for
>> qemux86*, this
>> patch just fixes the compilation error. It would probably not be able
>> to run on
>> qemux86* with corei7 tune.
> I don't think overriding arch values in recipe is appropriate. Also the
> recipe is setting COMPATIBLE_MACHINE to be null because of this reason.
> If the MACHINE that we're building for doesn't support the features
> required, then we shouldn't be building dpdk for it in my opinion.

This is largely a fix for those who want to test building qemux86* with dpdk.
It does no harm to the rest of the configuration, and can be use as a way to
append potential flags to dpdk building command line.

But it's fine to me to drop it if it does not make much sense to you.

Thanks,
Zhe

>
> Thanks,
>
> Anuj
>
>> Signed-off-by: He Zhe <zhe.he at windriver.com>
>> ---
>>  recipes-extended/dpdk/dpdk.inc | 9 ++++++---
>>  1 file changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/recipes-extended/dpdk/dpdk.inc b/recipes-
>> extended/dpdk/dpdk.inc
>> index a0e081a..0275e0c 100644
>> --- a/recipes-extended/dpdk/dpdk.inc
>> +++ b/recipes-extended/dpdk/dpdk.inc
>> @@ -61,6 +61,9 @@ DPDK_RTE_TARGET_x86-64 = "x86_64-native-linuxapp-
>> gcc"
>>  DPDK_RTE_TARGET_x86 = "i686-native-linuxapp-gcc"
>>  DPDK_RTE_TARGET_aarch64 = "arm64-${DPDK_TARGET_MACH}-linuxapp-gcc"
>>  export RTE_TARGET = "${DPDK_RTE_TARGET}"
>> +DPDK_EXTRA_CFLAGS = ""
>> +DPDK_EXTRA_CFLAGS_qemux86 ?= "-march=corei7"
>> +DPDK_EXTRA_CFLAGS_qemux86-64 ?= "-march=corei7"
>>  
>>  # The list of intel Comms platforms and their target machine
>>  # process mapping. The supported target machine is listed under
>> @@ -100,18 +103,18 @@ do_compile () {
>>  
>>  	cd ${S}/${RTE_TARGET}
>>  	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu" 
>> \
>> -		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> -I${STAGING_INCDIR}" \
>> +		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
>>  		   CROSS="${TARGET_PREFIX}" \
>>  		   prefix=""  LDFLAGS="${TUNE_LDARGS}"  WERROR_FLAGS="-
>> w" V=1
>>  
>>  	cd ${S}/examples/
>>  	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu
>> -fuse-ld=bfd" \
>> -		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> -I${STAGING_INCDIR}" \
>> +		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
>>  		   CROSS="${TARGET_PREFIX}" O="${S}/examples/$@/"
>>  
>>  	cd ${S}/test/
>>  	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu
>> -fuse-ld=bfd" \
>> -		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> -I${STAGING_INCDIR}" \
>> +		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS}
>> ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
>>  		   CROSS="${TARGET_PREFIX}" O="${S}/test/$@/"
>>  }
>>