Cache Latencies and Sizes on RAMCloud Test Cluster

Here are the appropriate latencies we incur from missing each layer of cache.

  • L1 Cache: 3 ns
  • L2 Cache: 13 ns
  • L3 Cache: 85 ns

Here is some general information about cache size and shape on the rcXX machines.

/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size:64
/sys/devices/system/cpu/cpu0/cache/index0/level:1
/sys/devices/system/cpu/cpu0/cache/index0/number_of_sets:64
/sys/devices/system/cpu/cpu0/cache/index0/physical_line_partition:1
/sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_list:0,4
/sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map:11
/sys/devices/system/cpu/cpu0/cache/index0/size:32K
/sys/devices/system/cpu/cpu0/cache/index0/type:Data
/sys/devices/system/cpu/cpu0/cache/index0/ways_of_associativity:8
/sys/devices/system/cpu/cpu0/cache/index1/coherency_line_size:64
/sys/devices/system/cpu/cpu0/cache/index1/level:1
/sys/devices/system/cpu/cpu0/cache/index1/number_of_sets:128
/sys/devices/system/cpu/cpu0/cache/index1/physical_line_partition:1
/sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_list:0,4
/sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map:11
/sys/devices/system/cpu/cpu0/cache/index1/size:32K
/sys/devices/system/cpu/cpu0/cache/index1/type:Instruction
/sys/devices/system/cpu/cpu0/cache/index1/ways_of_associativity:4
/sys/devices/system/cpu/cpu0/cache/index2/coherency_line_size:64
/sys/devices/system/cpu/cpu0/cache/index2/level:2
/sys/devices/system/cpu/cpu0/cache/index2/number_of_sets:512
/sys/devices/system/cpu/cpu0/cache/index2/physical_line_partition:1
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_list:0,4
/sys/devices/system/cpu/cpu0/cache/index2/shared_cpu_map:11
/sys/devices/system/cpu/cpu0/cache/index2/size:256K
/sys/devices/system/cpu/cpu0/cache/index2/type:Unified
/sys/devices/system/cpu/cpu0/cache/index2/ways_of_associativity:8
/sys/devices/system/cpu/cpu0/cache/index3/coherency_line_size:64
/sys/devices/system/cpu/cpu0/cache/index3/level:3
/sys/devices/system/cpu/cpu0/cache/index3/number_of_sets:8192
/sys/devices/system/cpu/cpu0/cache/index3/physical_line_partition:1
/sys/devices/system/cpu/cpu0/cache/index3/shared_cpu_list:0-7
/sys/devices/system/cpu/cpu0/cache/index3/shared_cpu_map:ff
/sys/devices/system/cpu/cpu0/cache/index3/size:8192K
/sys/devices/system/cpu/cpu0/cache/index3/type:Unified
/sys/devices/system/cpu/cpu0/cache/index3/ways_of_associativity:16