On Thu, Nov 23, 2017 at 06:36:07PM -0800, Jakub Kicinski wrote: > Hi! > > The purpose of this series is to add a software model of BPF offloads > to make it easier for everyone to test them and make some of the more > arcane rules and assumptions more clear. > > The series starts with 3 patches aiming to make XDP handling in the > drivers less error prone. Currently driver authors have to remember > to free XDP programs if XDP is active during unregister. With this > series the core will disable XDP on its own. It will take place > after close, drivers are not expected to perform reconfiguration > when disabling XDP on a downed device. > > Next two patches add the software netdev driver. Last but not least > there is a python test which exercises all the corner cases which > came to my mind. > > Test needs to be run as root. It will print basic information to > stdout, but can also create a more detailed log of all commands > when --log option is passed. Log is in Emacs Org-mode format. > > ./tools/testing/selftests/bpf/test_offload.py --log /tmp/log > > Something I'm still battling with, and would appreciate help of > wiser people is that occasionally during the test something makes > the refcount of init_net drop to 0 :S I tried to create a simple > reproducer, but seems like just running the script in the loop is > the easiest way to go... Could it have something to do with the > recent TC work? The driver is pretty simple and never touches > ref counts. The only slightly unusual thing is that the BPF code > sleeps for a bit on remove in the netdev notifier.
I like the direction. Patch 3 in particular with auto prog_put is a great idea! Patch 4 - if you want to do dual gpl+bsd. It's ok and really your call as an author. Patch 5 - I'm only not excited about debugfs. Can you do the same with tracepoints? Patch 6 - python 3 is a requirement? or can work with 2.7 ? I don't mind if it's 3+ only. Just trying to understand the dependencies. and thanks for adding it to selftests.
