On Mon, 12 Mar 2018 16:15:41 -0400 Waiman Long <longman@xxxxxxxxxx> wrote: > Even with clamped sysctl parameters, it is still not that straight > forward to figure out the exact range of those parameters. One may > try to write extreme parameter values to see if they get clamped. > To make it easier, a warning with the expected range will now be > printed into the kernel ring buffer when a clamped sysctl parameter > receives an out of range value. > > The pr_warn_ratelimited() macro is used to limit the number of warning > messages that can be printed within a given period of time. > > ... > > +#ifdef pr_fmt > +#undef pr_fmt > +#endif > +#define pr_fmt(fmt) "sysctl: " fmt Why is it necessary to undefine pr_fmt? That's a somewhat unusual thing to do.
