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 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 9922c69b0..4033e28eb 100644 --- a/acinclude.m4 +++ b/acinclude.m4 @@ -433,7 +433,13 @@ 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' + # 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]) -- 2.13.6 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev