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.
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
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
-cpu_possible_map.
+cpu_possible_mask.
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
[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
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
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
smp_num_probed = 1;
}
- printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
+ printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
smp_num_probed, cpumask_bits(cpu_present_mask)[0]);
}
early_param("additional_cpus", setup_additional_cpus);
/*
- * cpu_possible_map should be static, it cannot change as CPUs
+ * cpu_possible_mask should be static, it cannot change as CPUs
* are onlined, or offlined. The reason is per-cpu data-structures
* are allocated by some modules at init time, and dont expect to
* do this dynamically on cpu arrival/departure.
}
/**
- * Detect available CPUs, populate cpu_possible_map
+ * Detect available CPUs, populate cpu_possible_mask
*/
static void octeon_smp_hotplug_setup(void)
{
}
/*
- * Detect available CPUs, populate cpu_possible_map before smp_init
+ * Detect available CPUs, populate cpu_possible_mask before smp_init
*
* We don't want to start the secondary CPU yet nor do we have a nice probing
* feature in PMON so we just assume presence of the secondary core.
/*
* Use CFE to find out how many CPUs are available, setting up
- * cpu_possible_map and the logical/physical mappings.
+ * cpu_possible_mask and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
/*
* cpu_cacheable_map lists all the cpus whose caches the hypervisor can
- * flush on our behalf. It is set to cpu_possible_map OR'ed with
+ * flush on our behalf. It is set to cpu_possible_mask OR'ed with
* hash_for_home_map, and it is what should be passed to
* hv_flush_remote() to flush all caches. Note that if there are
* dedicated hypervisor driver tiles that have authorized use of their
xen_setup_mfn_list_list();
}
-/* This is called once we have the cpu_possible_map */
+/* This is called once we have the cpu_possible_mask */
void xen_setup_vcpu_info_placement(void)
{
int cpu;
config INIT_ALL_POSSIBLE
bool
help
- Back when each arch used to define their own cpu_online_map and
- cpu_possible_map, some of them chose to initialize cpu_possible_map
+ Back when each arch used to define their own cpu_online_mask and
+ cpu_possible_mask, some of them chose to initialize cpu_possible_mask
with all 1s, and others with all 0s. When they were centralised,
it was better to provide this option than to break all the archs
and have several arch maintainers pursuing me down dark alleys.
* are online. If none are online, walk up the cpuset hierarchy
* until we find one that does have some online cpus. If we get
* all the way to the top and still haven't found any online cpus,
- * return cpu_online_map. Or if passed a NULL cs from an exit'ing
- * task, return cpu_online_map.
+ * return cpu_online_mask. Or if passed a NULL cs from an exit'ing
+ * task, return cpu_online_mask.
*
* One way or another, we guarantee to return some non-empty subset
- * of cpu_online_map.
+ * of cpu_online_mask.
*
* Call with callback_mutex held.
*/
int retval;
int is_load_balanced;
- /* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
+ /* top_cpuset.cpus_allowed tracks cpu_online_mask; it's read-only */
if (cs == &top_cpuset)
return -EACCES;
*
* Description: Returns the cpumask_var_t cpus_allowed of the cpuset
* attached to the specified @tsk. Guaranteed to return some non-empty
- * subset of cpu_online_map, even if this means going outside the
+ * subset of cpu_online_mask, even if this means going outside the
* tasks cpuset.
**/
projects / linux-flexiantxendom0-3.2.10.git / commitdiff