diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 39 | ||||
| -rw-r--r-- | Documentation/cputopology.txt | 47 |
2 files changed, 69 insertions, 17 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 871acdbeed1a..2ade5c0809a0 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -38,6 +38,45 @@ Description: CPU topology files that describe kernel limits related to See Documentation/cputopology.txt for more information. +What: /sys/devices/system/cpu/cpu#/topology/core_id + /sys/devices/system/cpu/cpu#/topology/core_siblings + /sys/devices/system/cpu/cpu#/topology/core_siblings_list + /sys/devices/system/cpu/cpu#/topology/physical_package_id + /sys/devices/system/cpu/cpu#/topology/thread_siblings + /sys/devices/system/cpu/cpu#/topology/thread_siblings_list +Date: December 2008 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: CPU topology files that describe a logical CPU's relationship + to other cores and threads in the same physical package. + + One cpu# directory is created per logical CPU in the system, + e.g. /sys/devices/system/cpu/cpu42/. + + Briefly, the files above are: + + core_id: the CPU core ID of cpu#. Typically it is the + hardware platform's identifier (rather than the kernel's). + The actual value is architecture and platform dependent. + + core_siblings: internal kernel map of cpu#'s hardware threads + within the same physical_package_id. + + core_siblings_list: human-readable list of the logical CPU + numbers within the same physical_package_id as cpu#. + + physical_package_id: physical package id of cpu#. Typically + corresponds to a physical socket number, but the actual value + is architecture and platform dependent. + + thread_siblings: internel kernel map of cpu#'s hardware + threads within the same core as cpu# + + thread_siblings_list: human-readable list of cpu#'s hardware + threads within the same core as cpu# + + See Documentation/cputopology.txt for more information. + + What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X Date: August 2008 KernelVersion: 2.6.27 diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index b41f3e58aefa..f1c5c4bccd3e 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -1,15 +1,28 @@ -Export cpu topology info via sysfs. Items (attributes) are similar +Export CPU topology info via sysfs. Items (attributes) are similar to /proc/cpuinfo. 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: -represent the physical package id of cpu X; + + physical package id of cpuX. Typically corresponds to a physical + socket number, but the actual value is architecture and platform + dependent. + 2) /sys/devices/system/cpu/cpuX/topology/core_id: -represent the cpu core id to cpu X; + + the CPU core ID of cpuX. Typically it is the hardware platform's + identifier (rather than the kernel's). The actual value is + architecture and platform dependent. + 3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: -represent the thread siblings to cpu X in the same core; + + internel kernel map of cpuX's hardware threads within the same + core as cpuX + 4) /sys/devices/system/cpu/cpuX/topology/core_siblings: -represent the thread siblings to cpu X in the same physical package; + + internal kernel map of cpuX's hardware threads within the same + physical_package_id. To implement it in an architecture-neutral way, a new source file, drivers/base/topology.c, is to export the 4 attributes. @@ -32,32 +45,32 @@ not defined by include/asm-XXX/topology.h: 3) thread_siblings: just the given CPU 4) core_siblings: just the given CPU -Additionally, cpu topology information is provided under +Additionally, CPU topology information is provided under /sys/devices/system/cpu and includes these files. The internal source for the output is in brackets ("[]"). - kernel_max: the maximum cpu index allowed by the kernel configuration. + kernel_max: the maximum CPU index allowed by the kernel configuration. [NR_CPUS-1] - offline: cpus that are not online because they have been + offline: CPUs that are not online because they have been HOTPLUGGED off (see cpu-hotplug.txt) or exceed the limit - of cpus allowed by the kernel configuration (kernel_max + of CPUs allowed by the kernel configuration (kernel_max above). [~cpu_online_mask + cpus >= NR_CPUS] - online: cpus that are online and being scheduled [cpu_online_mask] + online: CPUs that are online and being scheduled [cpu_online_mask] - possible: cpus that have been allocated resources and can be + possible: CPUs that have been allocated resources and can be brought online if they are present. [cpu_possible_mask] - present: cpus that have been identified as being present in the + present: CPUs that have been identified as being present in the system. [cpu_present_mask] The format for the above output is compatible with cpulist_parse() [see <linux/cpumask.h>]. Some examples follow. -In this example, there are 64 cpus in the system but cpus 32-63 exceed +In this example, there are 64 CPUs in the system but cpus 32-63 exceed the kernel max which is limited to 0..31 by the NR_CPUS config option -being 32. Note also that cpus 2 and 4-31 are not online but could be +being 32. Note also that CPUs 2 and 4-31 are not online but could be brought online as they are both present and possible. kernel_max: 31 @@ -67,8 +80,8 @@ brought online as they are both present and possible. present: 0-31 In this example, the NR_CPUS config option is 128, but the kernel was -started with possible_cpus=144. There are 4 cpus in the system and cpu2 -was manually taken offline (and is the only cpu that can be brought +started with possible_cpus=144. There are 4 CPUs in the system and cpu2 +was manually taken offline (and is the only CPU that can be brought online.) kernel_max: 127 @@ -78,4 +91,4 @@ online.) present: 0-3 See cpu-hotplug.txt for the possible_cpus=NUM kernel start parameter -as well as more information on the various cpumask's. +as well as more information on the various cpumasks. |