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 <[email protected]> > Co-authored-by: Ilya Maximets <[email protected]> > Signed-off-by: Ian Stokes <[email protected]> > --- > 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' > + # 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 [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
