[HELP] Documentation on CPU:/sys/devices/system/cpu/cpuX/cache/indexX/shared_cpu_map

Hi all: Can anybody help me to understand the usage of 'shared_cpu_map' in /sys/devices/system/cpu/cpuX/cache/indexX/. when I execute the cmd--'#cat shared_cpu_map', it retures '05'. And my computer use Ubuntu12.04,Intel core i3 CPU. I have read one email in LKML,it says: "The patch also adds a bunch of interfaces under /sys/devices/system/cpu/cpuX/cache, showing various information about the caches. Most useful field being shared_cpu_map, which says what caches are shared among which logical cpus. " But I still cannot catch the meaning of 'which says what caches are shared among which logical cpus'. Thanks. -- Sincerely, Ren Zhen