1. 26 9月, 2012 1 次提交
    • H
      s390/cache: expose cpu cache topology via sysfs · 881730ad
      Heiko Carstens 提交于
      Expose cpu cache topology via sysfs.
      The created sysfs directory structure is compatible to what x86, ia64
      and powerpc have.
      On s390 we expose only information about cpu caches which are private
      to a cpu via sysfs . Caches which are shared between cpus do not have
      a sysfs representation.
      The reason for that is that the file "shared_cpu_map" is mandatory
      and only if running under LPAR it is possible to tell which cpus
      share which cache. Second level hypervisors however do not and cannot
      expose that information to guests.
      In order to have a consistent view we made the choice to always only
      expose information about private cpu caches via sysfs.
      
      Example for a z196 cpu (cpu1 in /sys/devices/cpu):
      
      cpu1/cache/index0/size -- 64K
      cpu1/cache/index0/type -- Data
      cpu1/cache/index0/level -- 1
      cpu1/cache/index0/number_of_sets -- 64
      cpu1/cache/index0/shared_cpu_map -- 00000000,00000002
      cpu1/cache/index0/shared_cpu_list -- 1
      cpu1/cache/index0/coherency_line_size -- 256
      cpu1/cache/index0/ways_of_associativity -- 4
      cpu1/cache/index1/size -- 128K
      cpu1/cache/index1/type -- Instruction
      cpu1/cache/index1/level -- 1
      cpu1/cache/index1/number_of_sets -- 64
      cpu1/cache/index1/shared_cpu_map -- 00000000,00000002
      cpu1/cache/index1/shared_cpu_list -- 1
      cpu1/cache/index1/coherency_line_size -- 256
      cpu1/cache/index1/ways_of_associativity -- 8
      cpu1/cache/index2/size -- 1536K
      cpu1/cache/index2/type -- Unified
      cpu1/cache/index2/level -- 2
      cpu1/cache/index2/number_of_sets -- 512
      cpu1/cache/index2/shared_cpu_map -- 00000000,00000002
      cpu1/cache/index2/shared_cpu_list -- 1
      cpu1/cache/index2/coherency_line_size -- 256
      cpu1/cache/index2/ways_of_associativity -- 12
      Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      881730ad