From: Bartosz Golaszewski <bgolaszewski+renesas@xxxxxxxxxxxx> The documentation on cpu topology seems to be a bit out-of-date. It doesn't mention the **_siblings_list attributes and uses old names for topology_**_cpumask() macros. Add information on missing attributes plus some minor clarifications. Signed-off-by: Bartosz Golaszewski <bgolaszewski+renesas@xxxxxxxxxxxx> --- NOTE: Forgot to add linux-doc on previous submission. Documentation/cputopology.txt | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index 0aad6de..27e67d7 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -1,6 +1,6 @@ Export CPU topology info via sysfs. Items (attributes) are similar -to /proc/cpuinfo. +to /proc/cpuinfo output of some architectures: 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: @@ -23,20 +23,35 @@ to /proc/cpuinfo. 4) /sys/devices/system/cpu/cpuX/topology/thread_siblings: internal kernel map of cpuX's hardware threads within the same - core as cpuX + core as cpuX. -5) /sys/devices/system/cpu/cpuX/topology/core_siblings: +5) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list: + + human-readable list of cpuX's hardware threads within the same + core as cpuX. + +6) /sys/devices/system/cpu/cpuX/topology/core_siblings: internal kernel map of cpuX's hardware threads within the same physical_package_id. -6) /sys/devices/system/cpu/cpuX/topology/book_siblings: +7) /sys/devices/system/cpu/cpuX/topology/core_siblings_list: + + human-readable list of cpuX's hardware threads within the same + physical_package_id. + +8) /sys/devices/system/cpu/cpuX/topology/book_siblings: internal kernel map of cpuX's hardware threads within the same book_id. +9) /sys/devices/system/cpu/cpuX/topology/book_siblings_list: + + human-readable list of cpuX's hardware threads within the same + book_id. + To implement it in an architecture-neutral way, a new source file, -drivers/base/topology.c, is to export the 4 or 6 attributes. The two book +drivers/base/topology.c, is to export the 6 or 9 attributes. The three book related sysfs files will only be created if CONFIG_SCHED_BOOK is selected. For an architecture to support this feature, it must define some of @@ -48,16 +63,17 @@ these macros in include/asm-XXX/topology.h: #define topology_core_cpumask(cpu) #define topology_book_cpumask(cpu) -The type of **_id is int. -The type of siblings is (const) struct cpumask *. +The type of **_id macros is int. +The type of **_cpumask macros is (const) struct cpumask *. The latter +correspond with appropriate **_siblings sysfs attributes. To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are not defined by include/asm-XXX/topology.h: 1) physical_package_id: -1 2) core_id: 0 -3) thread_siblings: just the given CPU -4) core_siblings: just the given CPU +3) thread_cpumask: just the given CPU +4) core_cpumask: just the given CPU For architectures that don't support books (CONFIG_SCHED_BOOK) there are no default definitions for topology_book_id() and topology_book_cpumask(). -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
