mirror of https://gitee.com/openkylin/linux.git
Documentation: Update cputopology.txt
The documentation on cpu topology seems to be a bit out-of-date.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 additional clarifications. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Benoit Cousson <bcousson@baylibre.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <jdelvare@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/1432645896-12588-3-git-send-email-bgolaszewski@baylibre.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
parent
06931e6224
commit
54a5369487
|
@ -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 +63,18 @@ 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 (except for
|
||||
topology_sibling_cpumask() which corresponds with thread_siblings).
|
||||
|
||||
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) sibling_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().
|
||||
|
|
Loading…
Reference in New Issue