Messages in this thread | | | Subject | Re: [PATCH] ppc64 ftrace: mark data_access callees "notrace" (pt.1) | From | Michael Ellerman <> | Date | Tue, 19 May 2015 13:27:07 +1000 |
| |
On Mon, 2015-05-18 at 14:29 +0200, Jiri Kosina wrote: > yOn Sat, 16 May 2015, Torsten Duwe wrote: > > > > > There's got to be a better solution than this. > > > > > > Can you think of a better approach? > > > > Maybe a per thread variable to lock out a recursion into tracing? > > Thanks for your doubt. > > ftrace already handles recursion protection by itself (depending on the > per-ftrace-ops FTRACE_OPS_FL_RECURSION_SAFE flag).
OK, so I wonder why that's not working for us?
> It's however not really well-defined what to do when recursion would > happen. Therefore __notrace__ annotation, that just completely avoid such > situation by making tracing impossible, looks like saner general solution > to me.
I disagree. Correctly annotating all functions that might be called ever and for all time is a maintenance nightmare and is never going to work in the long term.
cheers
| |