On Mon, 2019-10-14 at 10:42 +0000, Luis Chamberlain wrote: > On Fri, Sep 13, 2019 at 02:02:47PM -0700, Brendan Higgins wrote: > > Hey Knut and Shuah, > > > > Following up on our offline discussion on Wednesday night: > > > > We decided that it would make sense for Knut to try to implement Hybrid > > Testing (testing that crosses the kernel userspace boundary) that he > > introduced here[1] on top of the existing KUnit infrastructure. > > > > We discussed several possible things in the kernel that Knut could test > > with the new Hybrid Testing feature as an initial example. Those were > > (in reverse order of expected difficulty): > > > > 1. RDS (Reliable Datagram Sockets) - We decided that, although this was > > one of the more complicated subsystems to work with, it was probably > > the best candidate for Knut to start with because it was in desperate > > need of better testing, much of the testing would require crossing > > the kernel userspace boundary to be effective, and Knut has access to > > RDS (since he works at Oracle). > > > > 2. KMOD - Probably much simpler than RDS, and the maintainer, Luis > > Chamberlain (CC'ed) would like to see better testing here, but > > probably still not as good as RDS because it is in less dire need of > > testing, collaboration on this would be more difficult, and Luis is > > currently on an extended vacation. Luis and I had already been > > discussing testing KMOD here[2]. > > I'm back! > > I'm also happy and thrilled to help review the infrastructure in great > detail given I have lofty future objectives with testing in the kernel. > Also, kmod is a bit more complex to test, if Knut wants a simpler *easy* > target I think test_sysctl.c would be a good target. I think the goal > there would be to add probes for a few of the sysctl callers, and then > test them through userspace somehow, for instance? That sounds like a good case for the hybrid tests. The challenge in a kunit setting would be that it relies on a significant part of KTF to work as we have used it so far: - module support - Alan has been working on this - netlink approach from KTF (to allow user space execution of kernel part of test, and gathering reporting in one place) - probe infrastructure > The complexities with testing kmod is the threading aspect. So that is > more of a challenge for a test infrastructure as a whole. However kmod > also already has a pretty sound kthread solution which could be used > as basis for any sound kernel multithread test solution. > > Curious, what was decided with the regards to the generic netlink approach? I think in some way functionality similar to the netlink support is needed for the features in KTF that we discussed, so I get it is a "yes" to add support for it? Knut > Luis
