On 12/18/18 12:53 PM, shuah wrote: > On 12/18/18 4:37 AM, Rafael David Tinoco wrote: >> On 12/17/18 4:42 PM, shuah wrote: >>> Hi Rafael, >>> >>> On 12/17/18 10:53 AM, Rafael David Tinoco wrote: >>>> Shuah, >>>> >>>> I was recently investigating some errors coming out of our functional >>>> tests and we, Dan and I, came up with a discussion that might not be >>>> new >>>> for you, but, interests us, in defining how to better use kselftests as >>>> a regression mechanism/tool in our LKFT (https://lkft.linaro.org). >>>> >>>> David / Willem, >>>> >>>> I'm only using udpgso as an example for what I'd like to ask Shuah. >>>> Feel >>>> free to jump in in the discussion if you think its worth. >>>> >>>> All, >>>> >>>> Regarding: udpgso AND https://bugs.linaro.org/show_bug.cgi?id=3980 >>>> >>>> udpgso tests are failing in kernels bellow 4.18 because of 2 main >>>> reasons: >>>> >>>> 1) udp4_ufo_fragment does not seem to demand the GSO SKB to be > than >>>> the MTU for older kernels (4th test case in udpgso.c). >>>> >>>> 2) setsockopt(...UDP_SEGMENT) support is not present for older kernels. >>>> (commits "udp: generate gso with UDP_SEGMENT" and its fixes seem to be >>>> needed). >>> >>> This case is easy right? Based on the test output below , I can see that >>> the failure is due to >>> >>> ./udpgso: setsockopt udp segment: Protocol not available. setsockopt() >>> is returning an error to clearly indicate that this options isn't >>> supported. This will be a test change to say test is a skip as opposed >>> to fail. >> >> You referred to (2). (1) isn't that straightforward. >> >>> We have a solution for this - test should SKIP as opposed to FAIL. >>> >>>> With that explained, finally the question/discussion: >>>> >>>> Shouldn't we enforce a versioning mechanism for tests that are testing >>>> recently added features ? I mean, some of the tests inside udpgso >>>> selftest are good enough for older kernels... >>> >>> Right - we do have generic way to handle that by detecting if feature is >>> supported and skip instead of using Kernel version which is going to be >>> hard to maintain. >> >> You can't distinguish case (1) failures between real failures OR older >> kernel behaving differently then testcase expects. >> >>>> >>>> But, because we have no control over "kernel features" and "supported >>>> test cases", we, Linaro, have to end up blacklisting all selftests that >>>> have new feature oriented tests, because one or two test cases only. >>>> > > Can you share the blacklisted tests? Sure! The following yaml file: https://github.com/Linaro/qa-reports-known-issues/blob/master/kselftests-production.yaml Contains a list of all "known issues" for kselftests running in LKFT. 1 entry example (this particular one): - environments: *environments_all notes: > LKFT: net: udpgso.sh PASS on 4.18 and failed on 4.17 and below projects: - lkft/linux-stable-rc-4.14-oe - lkft/linux-stable-rc-4.9-oe - lkft/linux-stable-rc-4.4-oe - lkft/linaro-hikey-stable-rc-4.4-oe test_names: - kselftest/net_udpgso.sh - kselftest-vsyscall-mode-none/net_udpgso.sh - kselftest-vsyscall-mode-native/net_udpgso.sh url: https://bugs.linaro.org/show_bug.cgi?id=3980 active: true intermittent: false Tells us: Its a known issue for all environments (arm, arm64, x86, x86_64, qemus, etc) and kernels 4.14, 4.9 and 4.4. The "url" shows our internal bug related to the known issue/investigation. With that, we don't consider it as a regression when this test fails for 4.14, 4.9 and 4.4 in any existing environment (boards, qemu/kvm, hosts, diff archs). I hope it helps you, Cheers o/ -- Rafael D. Tinoco Linaro - Kernel Validation
