path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2012-04-02 08:53:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-04-02 08:53:24 -0700
commitdeb74f5ca1f22f9e1c5da93143a250dbb96535af (patch)
treeee9eb01e5433ea50f3414a469521a4c1cfaccb7a /Documentation
parentdd775ae2549217d3ae09363e3edb305d0fa19928 (diff)
parent615399c84d1b8d8d8752629e5e5ab4e5044d6918 (diff)
Merge tag 'for-linus' of git://github.com/rustyrussell/linux
Pull cpumask cleanups from Rusty Russell: "(Somehow forgot to send this out; it's been sitting in linux-next, and if you don't want it, it can sit there another cycle)" I'm a sucker for things that actually delete lines of code. Fix up trivial conflict in arch/arm/kernel/kprobes.c, where Rusty fixed a user of &cpu_online_map to be cpu_online_mask, but that code got deleted by commit b21d55e98ac2 ("ARM: 7332/1: extract out code patch function from kprobes"). * tag 'for-linus' of git://github.com/rustyrussell/linux: cpumask: remove old cpu_*_map. documentation: remove references to cpu_*_map. drivers/cpufreq/db8500-cpufreq: remove references to cpu_*_map. remove references to cpu_*_map in arch/
Diffstat (limited to 'Documentation')
2 files changed, 12 insertions, 12 deletions
diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt
index 5c51ed406d1d..cefd3d8bbd11 100644
--- a/Documentation/cgroups/cpusets.txt
+++ b/Documentation/cgroups/cpusets.txt
@@ -217,7 +217,7 @@ and name space for cpusets, with a minimum of additional kernel code.
The cpus and mems files in the root (top_cpuset) cpuset are
read-only. The cpus file automatically tracks the value of
-cpu_online_map using a CPU hotplug notifier, and the mems file
+cpu_online_mask using a CPU hotplug notifier, and the mems file
automatically tracks the value of node_states[N_HIGH_MEMORY]--i.e.,
nodes with memory--using the cpuset_track_online_nodes() hook.
diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index a20bfd415e41..66ef8f35613d 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -47,7 +47,7 @@ maxcpus=n Restrict boot time cpus to n. Say if you have 4 cpus, using
other cpus later online, read FAQ's for more info.
additional_cpus=n (*) Use this to limit hotpluggable cpus. This option sets
- cpu_possible_map = cpu_present_map + additional_cpus
+ cpu_possible_mask = cpu_present_mask + additional_cpus
cede_offline={"off","on"} Use this option to disable/enable putting offlined
processors to an extended H_CEDE state on
@@ -64,11 +64,11 @@ should only rely on this to count the # of cpus, but *MUST* not rely
on the apicid values in those tables for disabled apics. In the event
BIOS doesn't mark such hot-pluggable cpus as disabled entries, one could
use this parameter "additional_cpus=x" to represent those cpus in the
possible_cpus=n [s390,x86_64] use this to set hotpluggable cpus.
This option sets possible_cpus bits in
- cpu_possible_map. Thus keeping the numbers of bits set
+ cpu_possible_mask. Thus keeping the numbers of bits set
constant even if the machine gets rebooted.
CPU maps and such
@@ -76,7 +76,7 @@ CPU maps and such
[More on cpumaps and primitive to manipulate, please check
include/linux/cpumask.h that has more descriptive text.]
-cpu_possible_map: Bitmap of possible CPUs that can ever be available in the
+cpu_possible_mask: Bitmap of possible CPUs that can ever be available in the
system. This is used to allocate some boot time memory for per_cpu variables
that aren't designed to grow/shrink as CPUs are made available or removed.
Once set during boot time discovery phase, the map is static, i.e no bits
@@ -84,13 +84,13 @@ are added or removed anytime. Trimming it accurately for your system needs
upfront can save some boot time memory. See below for how we use heuristics
in x86_64 case to keep this under check.
-cpu_online_map: Bitmap of all CPUs currently online. Its set in __cpu_up()
+cpu_online_mask: Bitmap of all CPUs currently online. Its set in __cpu_up()
after a cpu is available for kernel scheduling and ready to receive
interrupts from devices. Its cleared when a cpu is brought down using
__cpu_disable(), before which all OS services including interrupts are
migrated to another target CPU.
-cpu_present_map: Bitmap of CPUs currently present in the system. Not all
+cpu_present_mask: Bitmap of CPUs currently present in the system. Not all
of them may be online. When physical hotplug is processed by the relevant
subsystem (e.g ACPI) can change and new bit either be added or removed
from the map depending on the event is hot-add/hot-remove. There are currently
@@ -99,22 +99,22 @@ at which time hotplug is disabled.
You really dont need to manipulate any of the system cpu maps. They should
be read-only for most use. When setting up per-cpu resources almost always use
-cpu_possible_map/for_each_possible_cpu() to iterate.
+cpu_possible_mask/for_each_possible_cpu() to iterate.
Never use anything other than cpumask_t to represent bitmap of CPUs.
#include <linux/cpumask.h>
- for_each_possible_cpu - Iterate over cpu_possible_map
- for_each_online_cpu - Iterate over cpu_online_map
- for_each_present_cpu - Iterate over cpu_present_map
+ for_each_possible_cpu - Iterate over cpu_possible_mask
+ for_each_online_cpu - Iterate over cpu_online_mask
+ for_each_present_cpu - Iterate over cpu_present_mask
for_each_cpu_mask(x,mask) - Iterate over some random collection of cpu mask.
#include <linux/cpu.h>
get_online_cpus() and put_online_cpus():
The above calls are used to inhibit cpu hotplug operations. While the
-cpu_hotplug.refcount is non zero, the cpu_online_map will not change.
+cpu_hotplug.refcount is non zero, the cpu_online_mask will not change.
If you merely need to avoid cpus going away, you could also use
preempt_disable() and preempt_enable() for those sections.
Just remember the critical section cannot call any