内核中 cpumask 相关操作分析 //待续

假设BITS_PER_LONG为32bit，NR_CPUS为 .那么，

const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] 如下：

	0
0
1	1<<0
2	1<<1
3	1<<2
4	1<<3
5	1<<4
6	1<<5
7	1<<6
8	1<<7
9	1<<8
10	1<<9
11	1<<10
12	1<<11
13	1<<12
14	1<<13
15	1<<14
16	1<<15
17	1<<16
18	1<<17
19	1<<18
20	1<<19
21	1<<20
22	1<<21
23	1<<22
24	1<<23
25	1<<24
26	1<<25
27	1<<26
28	1<<27
29	1<<28
30	1<<29
31	1<<30
32	1<<31