On Thu, Mar 10, 2022 at 8:39 PM Sanford, Robert <rsanf...@akamai.com> wrote: > > Hi Dan, > Thanks for the response. It is a lot of work and patience to get a change > accepted. I admire all the guys who do it on a regular basis. > > My problem turns out to be twofold: 1) Build machine has a CPU flag that the > target does not have, and I was building "native". > 2) Since I was building native, I was enabling RDSEED instructions even > though the CPU doesn't support them. Fortunately, getentropy(3) works in our > env. > > I found the answer, by digging into the meson.build files, especially in > config/ and config/x86/, and the resulting files created in the build dir. > Passing -Dplatform=haswell to meson did almost nothing AFAICS, still "native". > When I switch to -Dmachine=haswell, it has the desired effect on both > build.ninja (generating -march=haswell for gcc) > and rte_build_config.h (disabling RDSEED).
yeah I recall that the meson makefiles had a couple of changes that needed to be done. The patch worked by compiling the code with the RDSEED instructions regardless of whether or not the build platform supported them, but then checking the CPU flags at run time to see if it could be accessed or not. But that should work too, you just can't access RDSEED on platforms which support it, but whatever.. getentropy() will work. thanks dan
