> >+static int get_domain_id_from_scope(int cpu, enum resctrl_scope scope)
> >+{
> >+ switch (scope) {
> >+ case RESCTRL_L3_CACHE:
> >+ return get_cpu_cacheinfo_id(cpu, 3);
> >+ case RESCTRL_L2_CACHE:
> >+ return get_cpu_cacheinfo_id(cpu, 2);
> >+ default:
> >+ WARN_ON_ONCE(1);
> >+ break;
> >+ }
> >+
> >+ return -1;
> >+}
>
> Is there some reason the "return -1" is outside of the default switch
> case?
>
> Other switch statements in this patch do have returns inside the default
> case, is this one different in some way?
I've sometimes had compilers complain about code written:
static int get_domain_id_from_scope(int cpu, enum resctrl_scope scope)
{
switch (scope) {
case RESCTRL_L3_CACHE:
return get_cpu_cacheinfo_id(cpu, 3);
case RESCTRL_L2_CACHE:
return get_cpu_cacheinfo_id(cpu, 2);
default:
WARN_ON_ONCE(1);
return -1;
}
}
because they failed to notice that every path in the switch does a "return and they
issue a warning that the function has no return value because they don't realize
that the end of the function can't be reached.
So it's defensive programming against possible complier issues.
-Tony
