On 09/08/20 09:19, Phil Auld wrote: > Hi Quais, > > On Mon, Sep 07, 2020 at 12:02:24PM +0100 Qais Yousef wrote: > > On 09/02/20 09:54, Phil Auld wrote: > > > > > > > > I think this decoupling is not necessary. The natural place for those > > > > scheduler trace_event based on trace_points extension files is > > > > kernel/sched/ and here the internal sched.h can just be included. > > > > > > > > If someone really wants to build this as an out-of-tree module there is > > > > an easy way to make kernel/sched/sched.h visible. > > > > > > > > > > It's not so much that we really _want_ to do this in an external module. > > > But we aren't adding more trace events and my (limited) knowledge of > > > BPF let me to the conclusion that its raw tracepoint functionality > > > requires full events. I didn't see any other way to do it. > > > > I did have a patch that allowed that. It might be worth trying to upstream > > it. > > It just required a new macro which could be problematic. > > > > https://github.com/qais-yousef/linux/commit/fb9fea29edb8af327e6b2bf3bc41469a8e66df8b > > > > With the above I could attach using bpf::RAW_TRACEPOINT mechanism. > > > > Yeah, that could work. I meant there was no way to do it with what was there > :) > > In our initial attempts at using BPF to get at nr_running (which I was not > involved in and don't have all the details...) there were issues being able to > keep up and losing events. That may have been an implementation issue, but > using the module and trace-cmd doesn't have that problem. Hopefully you don't > see that using RAW_TRACEPOINTs.
I haven't played with that since then tbh. I use BPF every now and then, but rather simplistically. So if I encoutnered such a problem I wouldn't have noticed. > Fwiw, I don't think these little helper routines are all that hard to > maintain. > If something changes in those fields, which seems moderately unlikely at least > for many of them, the compiler will complain. > > And I agree with you about preferring to use the public headers for the > module. > I think we can work around it though, if needed. +1 Cheers -- Qais Yousef
