2.5.61: x86_64 num_online_cpus() buglet?

[Mikael Pettersson]

Andi,

Kernel 2.5.61's include/asm-x86_64/smp.h contains:

extern unsigned long cpu_online_map;
...
extern inline unsigned int num_online_cpus(void)
{ 
	return hweight32(cpu_online_map);
} 

and similarly for cpu_callout_map.

hweight32() truncates a 64-bit operand to 32-bits, so either
- the maps should be int rather than long, or
- x86_64 needs to define and use a new hweight64(), or
- CONFIG_NR_CPUS must not exceed 32 on x86_64.

Comments?

/Mikael