On Fri, Mar 6, 2020 at 12:55 PM Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote: > > ----- On Mar 6, 2020, at 3:45 PM, rostedt rostedt@xxxxxxxxxxx wrote: > > > On Fri, 6 Mar 2020 15:22:46 -0500 (EST) > > Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote: > > > >> I agree with the overall approach. Just a bit of nitpicking on the API: > >> > >> I understand that the "prio" argument is a separate argument because it can take > >> many values. However, "rcu" is just a boolean, so I wonder if we should not > >> rather > >> introduce a "int flags" with a bitmask enum, e.g. > > > > I thought about this approach, but thought it was a bit overkill. As the > > kernel doesn't have an internal API, I figured we can switch this over to > > flags when we get another flag to add. Unless you can think of one in the > > near future. > > The additional feature I have in mind for near future would be to register > a probe which can take a page fault to a "sleepable" tracepoint. This would > require preemption to be enabled and use of SRCU. I'm working on sleepable bpf as well and this extra flag for tracepoints would come very handy, so I would go with flags approach right away. We wouldn't need to touch the same protos multiple times, less conflicts for us all, etc.
