(2) 如查看cpu0 的一级缓存中的有多少组（每一份中有多少个cacheline）

$ cat /sys/devices/system/cpu/cpu0/cache/index0/number_of_sets
$128

14.3 查看cache_line的大小

上面以ls1043的cpu一级缓存为例知道了cpu0的一级缓存的大小：32k，其包含128个（sets）组，每组有4(ways),则可以算出每一个way(cache_line)的大小 cache_line = 321024/(1284)=64 bytes。当然我们也可以通过以下命令查出cache_line的大小(单位是字节)

# cat /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_siz
64

14.4 查看cache的分配策略

# cat /sys/devices/system/cpu/cpu0/cache/index0/alloction_policy
ReadWriteAllocate

# cat /sys/devices/system/cpu/cpu0/cache/index1/alloction_policy
ReadAllocate

# cat /sys/devices/system/cpu/cpu0/cache/index2/alloction_policy
ReadWriteAllocate

14.5 查看cache的回写策略

# cat /sys/devices/system/cpu/cpu0/cache/index0/write_policy
WriteBack

# cat /sys/devices/system/cpu/cpu0/cache/index1/write_policy
cat：can't open 'write_policy':No such file or directory 

# cat /sys/devices/system/cpu/cpu0/cache/index2/write_policy
WriteBack

14.5 查看cache的shared_cpu_map

# cat /sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map
1
# cat /sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map
1
# cat /sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_map
f

# cat /sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_map
2
# cat /sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_map
2
# cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map
f

# cat /sys/devices/system/cpu/cpu2/cache/index0/shared_cpu_map
4
# cat /sys/devices/system/cpu/cpu2/cache/index1/shared_cpu_map
4
# cat /sys/devices/system/cpu/cpu2/cache/index2/shared_cpu_map
f

# cat /sys/devices/system/cpu/cpu3/cache/index0/shared_cpu_map
8
# cat /sys/devices/system/cpu/cpu3/cache/index1/shared_cpu_map
8
# cat /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
f

14.6 查看cache的shared_cpu_list

# cat /sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_list
0
# cat /sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_list
0
# cat /sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_list
0-3

# cat /sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_list
1
# cat /sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_list
1
# cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list
0-3

# cat /sys/devices/system/cpu/cpu2/cache/index0/shared_cpu_list
2
# cat /sys/devices/system/cpu/cpu2/cache/index1/shared_cpu_list
2
# cat /sys/devices/system/cpu/cpu2/cache/index2/shared_cpu_list
0-3

# cat /sys/devices/system/cpu/cpu3/cache/index0/shared_cpu_list
3
# cat /sys/devices/system/cpu/cpu3/cache/index1/shared_cpu_list
3
# cat /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_list
0-3

部分章节摘自：
(1) Linux内存管理：ARM64体系结构与编程之cache（1）
(2) Linux内存管理：ARM64体系结构与编程之cache（2）：cache一致性
(3) Cache的基本知识
(4) 《Arm® Architecture Reference Manual Armv8, for Armv8-A architecture profile - The AArch64 System Level Memory Model D4.4 Cache support》
(5) DMA和cache一致性问题