On 1/20/21 7:07 PM, Stokes, Ian wrote: > >> On 1/15/21 7:13 PM, Ilya Maximets wrote: >>> On 1/15/21 6:38 PM, Ian Stokes wrote: >>>> DPDK forces '-mno-avx512f' flag for the application if the toolchain >>>> used to build DPDK had broken AVX512 support. >>>> >>>> DPDK forces '-mno-avx512f' flag for the application if the toolchain >>>> used to build DPDK had broken AVX512 support. But OVS could be built >>>> with a completely different or fixed toolchain with correct avx512 >>>> support. >>>> >>>> Fix that by stripping out `-mno-avx512f` as we already do for '-march'. >>>> This will allow the OVS to decide if the AVX512 can be used. >>>> >>>> Reordering of CFLAGS (i.e. adding DPDK flags before OVS ones) is not an >>>> option since autotools might reorder them back later and it's very >>>> unpredictable. >>>> >>>> Reported-at: openvswitch/ovs-issues#201 >>> >>> Same here. >>> I think, it's better to have a URL here. Could be changed on commit. >>> Otherwise, LGTM. >>> >>>> Signed-off-by: Ilya Maximets <i.maxim...@ovn.org> >>>> Co-authored-by: Ilya Maximets <i.maxim...@ovn.org> >>>> Signed-off-by: Ian Stokes <ian.sto...@intel.com> >>>> --- >>>> acinclude.m4 | 8 +++++++- >>>> 1 file changed, 7 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/acinclude.m4 b/acinclude.m4 >>>> index 14fe4218a..5710f5da8 100644 >>>> --- a/acinclude.m4 >>>> +++ b/acinclude.m4 >>>> @@ -438,7 +438,13 @@ AC_DEFUN([OVS_CHECK_DPDK], [ >>>> fi >>>> # Force in pkg-config since this could override user-specified >>>> options. >>>> # It's enough to have -mssse3 to build with DPDK headers. >>>> - DPDK_INCLUDE=$(echo "$DPDK_INCLUDE" | sed 's/-march=[[^ ]]*//g') >>>> + DPDK_INCLUDE=$(echo "$DPDK_INCLUDE" | sed 's/-march=[[^ ]]*//g' >> >> OK. I missed that during the review. >> > > Apologies Ilya, I can see it was moved to where the avx512 is stripped below. > Will add it back above and removed the extra ')' below. >
No problem. Thanks for fixing. > Regards > Ian >>>> + # Also stripping out '-mno-avx512f'. Support for AVX512 will be >> disabled >>>> + # if OVS will detect that it's broken. OVS could be built with a >>>> + # completely different toolchain that correctly supports AVX512, flags >>>> + # forced by DPDK only breaks our feature detection mechanism and >> leads to >>>> + # build failures: https://github.com/openvswitch/ovs- >> issues/issues/201 >>>> + DPDK_INCLUDE=$(echo "$DPDK_INCLUDE" | sed 's/-mno- >> avx512f//g')) >>>> OVS_CFLAGS="$OVS_CFLAGS $DPDK_INCLUDE" >>>> OVS_ENABLE_OPTION([-mssse3]) >>>> >>>> >>> > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
