Messages in this thread | | | From | Doug Anderson <> | Date | Fri, 4 Aug 2023 09:06:07 -0700 | Subject | Re: [PATCH v3 1/2] nmi_backtrace: Allow excluding an arbitrary CPU |
| |
Hi,
On Fri, Aug 4, 2023 at 8:02 AM Michal Hocko <mhocko@suse.com> wrote: > > > > It would have been slightly safer to modify arch_trigger_cpumask_backtrace > > > by switching arguments so that some leftovers are captured easier. > > > > I'm not sure I understand. Oh, you're saying make the prototype of > > arch_trigger_cpumask_backtrace() incompatible so that if someone is > > directly calling it then it'll be a compile-time error? > > exactly. bool to int promotion would be too easy to miss while the > pointer to int would complain loudly. > > > I guess the > > hope is that nobody is calling that directly and they're calling > > through the trigger_...() functions. > > Hope is one thing, being preventive another. > > > For now I'm going to leave this alone. > > If you are going to send another version then please consider this. Not > a hard requirement but better.
If I do send another version, do you have any suggestions for how to change this to make it incompatible? I guess swapping the order of the parameters would be best? I considered doing that for v4 but I felt like long term the current order of the parameters was better. I also considered a rename, but that different problems. ;-) If I rename both the #define and the function then if someone has an out-of-tree patch adding arch_trigger_cpumask_backtrace() for another architecture, like say arm64, then there would be no compile-time failure indicating that the out-of-tree patch needs updating. I could rename the functions but _not_ the #define, I guess?
| |