----- "Michael Holzheu" <holzheu(a)linux.vnet.ibm.com&gt; wrote: > > So yes, while STRUCT_SIZE("cpumask_t") would always be appropriate for that > > data type, it would fail for the older kernel types which don't use it. > > So if for older kernels it was an unsigned long, the function should > work: > > +static int > +cpu_map_size(void) > +{ > + int len; > + > + len = STRUCT_SIZE("cpumask_t"); > + if (len < 0) > + return sizeof(ulong); > + else > + return len; > +} Yeah, you're right, that will probably work. There were definitions for "cpumask_t" that existed prior to the transition of cpu_online_map symbol from being an unsigned long to a cpumask_t. But except for mips64 (unsupported) they all appear to have been unsigned longs anyway.