On Wed, Feb 5, 2020 at 1:48 PM Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, Feb 05, 2020 at 01:35:56PM -0800, Joel Fernandes wrote: > > On Wed, Feb 5, 2020 at 1:33 PM Greg Kroah-Hartman > > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > [snip] > > > > > like the BTF approach is significantly better and said users are > > > > > hopefully moving forward to it quickly, and if they can't move > > > > > forward, then they're likely also not going to move forward to newer > > > > > kernels either? > > > > > > > > I think BCC runs on a lot of upstream machines. I think the migration > > > > strategy is a matter of opinion, one way is to take it out and cause some > > > > pain in the hope that users/tools will migrate soon (while probably carrying > > > > the reverted patches out of tree). Another is to migrate the tools first and > > > > then take it out (which has its own disadvantages such as introducing even > > > > more users of it while it is still upstream). > > > > > > Do we "know" what tools today require this, and what needs to be done to > > > "fix" them? If we don't know that, then there's no way to drop this, > > > pretty much ever :( > > > > Is there a real reason to drop it or a problem dropping this solves though? > > Olof had some reasons, but as we were drinking at the time when it came > up last night, I can't really remember them specifically. Hopefully he > does :) > But that didn't answer my question of "who is still using this"? I was > hoping we actually knew this given it was created for specific users. I think I mentioned this in a previous thread of this email. Several BCC tools are using it - see for example the criticalstat BCC tool which includes linux/sched.h : https://github.com/iovisor/bcc/blob/master/tools/criticalstat.py#L73 , or filetop BCC tool which uses struct dentry : https://github.com/iovisor/bcc/blob/master/tools/filetop.py#L101 These would break without kernel headers either on the host or via CONFIG_IKHEADERS. thanks, - Joel
