![Mike Travis](/assets/img/avatar_default.png)
* This patch replaces the dangerous lvalue version of cpumask_of_cpu with new cpumask_of_cpu_ptr macros. These are patterned after the node_to_cpumask_ptr macros. In general terms, if there is a cpumask_of_cpu_map[] then a pointer to the cpumask_of_cpu_map[cpu] entry is used. The cpumask_of_cpu_map is provided when there is a large NR_CPUS count, reducing greatly the amount of code generated and stack space used for cpumask_of_cpu(). The pointer to the cpumask_t value is needed for calling set_cpus_allowed_ptr() to reduce the amount of stack space needed to pass the cpumask_t value. If there isn't a cpumask_of_cpu_map[], then a temporary variable is declared and filled in with value from cpumask_of_cpu(cpu) as well as a pointer variable pointing to this temporary variable. Afterwards, the pointer is used to reference the cpumask value. The compiler will optimize out the extra dereference through the pointer as well as the stack space used for the pointer, resulting in identical code. A good example of the orthogonal usages is in net/sunrpc/svc.c: case SVC_POOL_PERCPU: { unsigned int cpu = m->pool_to[pidx]; cpumask_of_cpu_ptr(cpumask, cpu); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, cpumask); return 1; } case SVC_POOL_PERNODE: { unsigned int node = m->pool_to[pidx]; node_to_cpumask_ptr(nodecpumask, node); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, nodecpumask); return 1; } Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
502 lines
18 KiB
C
502 lines
18 KiB
C
#ifndef __LINUX_CPUMASK_H
|
|
#define __LINUX_CPUMASK_H
|
|
|
|
/*
|
|
* Cpumasks provide a bitmap suitable for representing the
|
|
* set of CPU's in a system, one bit position per CPU number.
|
|
*
|
|
* See detailed comments in the file linux/bitmap.h describing the
|
|
* data type on which these cpumasks are based.
|
|
*
|
|
* For details of cpumask_scnprintf() and cpumask_parse_user(),
|
|
* see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
|
|
* For details of cpulist_scnprintf() and cpulist_parse(), see
|
|
* bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
|
|
* For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
|
|
* For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
|
|
* For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
|
|
* For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
|
|
*
|
|
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
|
* Note: The alternate operations with the suffix "_nr" are used
|
|
* to limit the range of the loop to nr_cpu_ids instead of
|
|
* NR_CPUS when NR_CPUS > 64 for performance reasons.
|
|
* If NR_CPUS is <= 64 then most assembler bitmask
|
|
* operators execute faster with a constant range, so
|
|
* the operator will continue to use NR_CPUS.
|
|
*
|
|
* Another consideration is that nr_cpu_ids is initialized
|
|
* to NR_CPUS and isn't lowered until the possible cpus are
|
|
* discovered (including any disabled cpus). So early uses
|
|
* will span the entire range of NR_CPUS.
|
|
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
|
*
|
|
* The available cpumask operations are:
|
|
*
|
|
* void cpu_set(cpu, mask) turn on bit 'cpu' in mask
|
|
* void cpu_clear(cpu, mask) turn off bit 'cpu' in mask
|
|
* void cpus_setall(mask) set all bits
|
|
* void cpus_clear(mask) clear all bits
|
|
* int cpu_isset(cpu, mask) true iff bit 'cpu' set in mask
|
|
* int cpu_test_and_set(cpu, mask) test and set bit 'cpu' in mask
|
|
*
|
|
* void cpus_and(dst, src1, src2) dst = src1 & src2 [intersection]
|
|
* void cpus_or(dst, src1, src2) dst = src1 | src2 [union]
|
|
* void cpus_xor(dst, src1, src2) dst = src1 ^ src2
|
|
* void cpus_andnot(dst, src1, src2) dst = src1 & ~src2
|
|
* void cpus_complement(dst, src) dst = ~src
|
|
*
|
|
* int cpus_equal(mask1, mask2) Does mask1 == mask2?
|
|
* int cpus_intersects(mask1, mask2) Do mask1 and mask2 intersect?
|
|
* int cpus_subset(mask1, mask2) Is mask1 a subset of mask2?
|
|
* int cpus_empty(mask) Is mask empty (no bits sets)?
|
|
* int cpus_full(mask) Is mask full (all bits sets)?
|
|
* int cpus_weight(mask) Hamming weigh - number of set bits
|
|
* int cpus_weight_nr(mask) Same using nr_cpu_ids instead of NR_CPUS
|
|
*
|
|
* void cpus_shift_right(dst, src, n) Shift right
|
|
* void cpus_shift_left(dst, src, n) Shift left
|
|
*
|
|
* int first_cpu(mask) Number lowest set bit, or NR_CPUS
|
|
* int next_cpu(cpu, mask) Next cpu past 'cpu', or NR_CPUS
|
|
* int next_cpu_nr(cpu, mask) Next cpu past 'cpu', or nr_cpu_ids
|
|
*
|
|
* cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set
|
|
*ifdef CONFIG_HAS_CPUMASK_OF_CPU
|
|
* cpumask_of_cpu_ptr_declare(v) Declares cpumask_t *v
|
|
* cpumask_of_cpu_ptr_next(v, cpu) Sets v = &cpumask_of_cpu_map[cpu]
|
|
* cpumask_of_cpu_ptr(v, cpu) Combines above two operations
|
|
*else
|
|
* cpumask_of_cpu_ptr_declare(v) Declares cpumask_t _v and *v = &_v
|
|
* cpumask_of_cpu_ptr_next(v, cpu) Sets _v = cpumask_of_cpu(cpu)
|
|
* cpumask_of_cpu_ptr(v, cpu) Combines above two operations
|
|
*endif
|
|
* CPU_MASK_ALL Initializer - all bits set
|
|
* CPU_MASK_NONE Initializer - no bits set
|
|
* unsigned long *cpus_addr(mask) Array of unsigned long's in mask
|
|
*
|
|
* int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
|
|
* int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask
|
|
* int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
|
|
* int cpulist_parse(buf, map) Parse ascii string as cpulist
|
|
* int cpu_remap(oldbit, old, new) newbit = map(old, new)(oldbit)
|
|
* void cpus_remap(dst, src, old, new) *dst = map(old, new)(src)
|
|
* void cpus_onto(dst, orig, relmap) *dst = orig relative to relmap
|
|
* void cpus_fold(dst, orig, sz) dst bits = orig bits mod sz
|
|
*
|
|
* for_each_cpu_mask(cpu, mask) for-loop cpu over mask using NR_CPUS
|
|
* for_each_cpu_mask_nr(cpu, mask) for-loop cpu over mask using nr_cpu_ids
|
|
*
|
|
* int num_online_cpus() Number of online CPUs
|
|
* int num_possible_cpus() Number of all possible CPUs
|
|
* int num_present_cpus() Number of present CPUs
|
|
*
|
|
* int cpu_online(cpu) Is some cpu online?
|
|
* int cpu_possible(cpu) Is some cpu possible?
|
|
* int cpu_present(cpu) Is some cpu present (can schedule)?
|
|
*
|
|
* int any_online_cpu(mask) First online cpu in mask
|
|
*
|
|
* for_each_possible_cpu(cpu) for-loop cpu over cpu_possible_map
|
|
* for_each_online_cpu(cpu) for-loop cpu over cpu_online_map
|
|
* for_each_present_cpu(cpu) for-loop cpu over cpu_present_map
|
|
*
|
|
* Subtlety:
|
|
* 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
|
|
* to generate slightly worse code. Note for example the additional
|
|
* 40 lines of assembly code compiling the "for each possible cpu"
|
|
* loops buried in the disk_stat_read() macros calls when compiling
|
|
* drivers/block/genhd.c (arch i386, CONFIG_SMP=y). So use a simple
|
|
* one-line #define for cpu_isset(), instead of wrapping an inline
|
|
* inside a macro, the way we do the other calls.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/threads.h>
|
|
#include <linux/bitmap.h>
|
|
|
|
typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
|
|
extern cpumask_t _unused_cpumask_arg_;
|
|
|
|
#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
|
|
static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
|
|
{
|
|
set_bit(cpu, dstp->bits);
|
|
}
|
|
|
|
#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
|
|
static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
|
|
{
|
|
clear_bit(cpu, dstp->bits);
|
|
}
|
|
|
|
#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
|
|
static inline void __cpus_setall(cpumask_t *dstp, int nbits)
|
|
{
|
|
bitmap_fill(dstp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
|
|
static inline void __cpus_clear(cpumask_t *dstp, int nbits)
|
|
{
|
|
bitmap_zero(dstp->bits, nbits);
|
|
}
|
|
|
|
/* No static inline type checking - see Subtlety (1) above. */
|
|
#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
|
|
|
|
#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
|
|
static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
|
|
{
|
|
return test_and_set_bit(cpu, addr->bits);
|
|
}
|
|
|
|
#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
|
|
static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
|
|
static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
|
|
static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_andnot(dst, src1, src2) \
|
|
__cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
|
|
static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
|
|
static inline void __cpus_complement(cpumask_t *dstp,
|
|
const cpumask_t *srcp, int nbits)
|
|
{
|
|
bitmap_complement(dstp->bits, srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
|
|
static inline int __cpus_equal(const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
return bitmap_equal(src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
|
|
static inline int __cpus_intersects(const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
return bitmap_intersects(src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
|
|
static inline int __cpus_subset(const cpumask_t *src1p,
|
|
const cpumask_t *src2p, int nbits)
|
|
{
|
|
return bitmap_subset(src1p->bits, src2p->bits, nbits);
|
|
}
|
|
|
|
#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
|
|
static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
|
|
{
|
|
return bitmap_empty(srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
|
|
static inline int __cpus_full(const cpumask_t *srcp, int nbits)
|
|
{
|
|
return bitmap_full(srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
|
|
static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
|
|
{
|
|
return bitmap_weight(srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_shift_right(dst, src, n) \
|
|
__cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
|
|
static inline void __cpus_shift_right(cpumask_t *dstp,
|
|
const cpumask_t *srcp, int n, int nbits)
|
|
{
|
|
bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
|
|
}
|
|
|
|
#define cpus_shift_left(dst, src, n) \
|
|
__cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
|
|
static inline void __cpus_shift_left(cpumask_t *dstp,
|
|
const cpumask_t *srcp, int n, int nbits)
|
|
{
|
|
bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
|
|
extern cpumask_t *cpumask_of_cpu_map;
|
|
#define cpumask_of_cpu(cpu) (cpumask_of_cpu_map[cpu])
|
|
#define cpumask_of_cpu_ptr(v, cpu) \
|
|
const cpumask_t *v = &cpumask_of_cpu(cpu)
|
|
#define cpumask_of_cpu_ptr_declare(v) \
|
|
const cpumask_t *v
|
|
#define cpumask_of_cpu_ptr_next(v, cpu) \
|
|
v = &cpumask_of_cpu(cpu)
|
|
#else
|
|
#define cpumask_of_cpu(cpu) \
|
|
({ \
|
|
typeof(_unused_cpumask_arg_) m; \
|
|
if (sizeof(m) == sizeof(unsigned long)) { \
|
|
m.bits[0] = 1UL<<(cpu); \
|
|
} else { \
|
|
cpus_clear(m); \
|
|
cpu_set((cpu), m); \
|
|
} \
|
|
m; \
|
|
})
|
|
#define cpumask_of_cpu_ptr(v, cpu) \
|
|
cpumask_t _##v = cpumask_of_cpu(cpu); \
|
|
const cpumask_t *v = &_##v
|
|
#define cpumask_of_cpu_ptr_declare(v) \
|
|
cpumask_t _##v; \
|
|
const cpumask_t *v = &_##v
|
|
#define cpumask_of_cpu_ptr_next(v, cpu) \
|
|
_##v = cpumask_of_cpu(cpu)
|
|
#endif
|
|
|
|
#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
|
|
|
|
#if NR_CPUS <= BITS_PER_LONG
|
|
|
|
#define CPU_MASK_ALL \
|
|
(cpumask_t) { { \
|
|
[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
|
|
} }
|
|
|
|
#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
|
|
|
|
#else
|
|
|
|
#define CPU_MASK_ALL \
|
|
(cpumask_t) { { \
|
|
[0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
|
|
[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
|
|
} }
|
|
|
|
/* cpu_mask_all is in init/main.c */
|
|
extern cpumask_t cpu_mask_all;
|
|
#define CPU_MASK_ALL_PTR (&cpu_mask_all)
|
|
|
|
#endif
|
|
|
|
#define CPU_MASK_NONE \
|
|
(cpumask_t) { { \
|
|
[0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \
|
|
} }
|
|
|
|
#define CPU_MASK_CPU0 \
|
|
(cpumask_t) { { \
|
|
[0] = 1UL \
|
|
} }
|
|
|
|
#define cpus_addr(src) ((src).bits)
|
|
|
|
#define cpumask_scnprintf(buf, len, src) \
|
|
__cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
|
|
static inline int __cpumask_scnprintf(char *buf, int len,
|
|
const cpumask_t *srcp, int nbits)
|
|
{
|
|
return bitmap_scnprintf(buf, len, srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpumask_parse_user(ubuf, ulen, dst) \
|
|
__cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
|
|
static inline int __cpumask_parse_user(const char __user *buf, int len,
|
|
cpumask_t *dstp, int nbits)
|
|
{
|
|
return bitmap_parse_user(buf, len, dstp->bits, nbits);
|
|
}
|
|
|
|
#define cpulist_scnprintf(buf, len, src) \
|
|
__cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
|
|
static inline int __cpulist_scnprintf(char *buf, int len,
|
|
const cpumask_t *srcp, int nbits)
|
|
{
|
|
return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
|
|
}
|
|
|
|
#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
|
|
static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
|
|
{
|
|
return bitmap_parselist(buf, dstp->bits, nbits);
|
|
}
|
|
|
|
#define cpu_remap(oldbit, old, new) \
|
|
__cpu_remap((oldbit), &(old), &(new), NR_CPUS)
|
|
static inline int __cpu_remap(int oldbit,
|
|
const cpumask_t *oldp, const cpumask_t *newp, int nbits)
|
|
{
|
|
return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_remap(dst, src, old, new) \
|
|
__cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
|
|
static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
|
|
const cpumask_t *oldp, const cpumask_t *newp, int nbits)
|
|
{
|
|
bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_onto(dst, orig, relmap) \
|
|
__cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
|
|
static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
|
|
const cpumask_t *relmapp, int nbits)
|
|
{
|
|
bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
|
|
}
|
|
|
|
#define cpus_fold(dst, orig, sz) \
|
|
__cpus_fold(&(dst), &(orig), sz, NR_CPUS)
|
|
static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
|
|
int sz, int nbits)
|
|
{
|
|
bitmap_fold(dstp->bits, origp->bits, sz, nbits);
|
|
}
|
|
|
|
#if NR_CPUS == 1
|
|
|
|
#define nr_cpu_ids 1
|
|
#define first_cpu(src) ({ (void)(src); 0; })
|
|
#define next_cpu(n, src) ({ (void)(src); 1; })
|
|
#define any_online_cpu(mask) 0
|
|
#define for_each_cpu_mask(cpu, mask) \
|
|
for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
|
|
|
|
#else /* NR_CPUS > 1 */
|
|
|
|
extern int nr_cpu_ids;
|
|
int __first_cpu(const cpumask_t *srcp);
|
|
int __next_cpu(int n, const cpumask_t *srcp);
|
|
int __any_online_cpu(const cpumask_t *mask);
|
|
|
|
#define first_cpu(src) __first_cpu(&(src))
|
|
#define next_cpu(n, src) __next_cpu((n), &(src))
|
|
#define any_online_cpu(mask) __any_online_cpu(&(mask))
|
|
#define for_each_cpu_mask(cpu, mask) \
|
|
for ((cpu) = -1; \
|
|
(cpu) = next_cpu((cpu), (mask)), \
|
|
(cpu) < NR_CPUS; )
|
|
#endif
|
|
|
|
#if NR_CPUS <= 64
|
|
|
|
#define next_cpu_nr(n, src) next_cpu(n, src)
|
|
#define cpus_weight_nr(cpumask) cpus_weight(cpumask)
|
|
#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
|
|
|
|
#else /* NR_CPUS > 64 */
|
|
|
|
int __next_cpu_nr(int n, const cpumask_t *srcp);
|
|
#define next_cpu_nr(n, src) __next_cpu_nr((n), &(src))
|
|
#define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
|
|
#define for_each_cpu_mask_nr(cpu, mask) \
|
|
for ((cpu) = -1; \
|
|
(cpu) = next_cpu_nr((cpu), (mask)), \
|
|
(cpu) < nr_cpu_ids; )
|
|
|
|
#endif /* NR_CPUS > 64 */
|
|
|
|
/*
|
|
* The following particular system cpumasks and operations manage
|
|
* possible, present and online cpus. Each of them is a fixed size
|
|
* bitmap of size NR_CPUS.
|
|
*
|
|
* #ifdef CONFIG_HOTPLUG_CPU
|
|
* cpu_possible_map - has bit 'cpu' set iff cpu is populatable
|
|
* cpu_present_map - has bit 'cpu' set iff cpu is populated
|
|
* cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
|
|
* #else
|
|
* cpu_possible_map - has bit 'cpu' set iff cpu is populated
|
|
* cpu_present_map - copy of cpu_possible_map
|
|
* cpu_online_map - has bit 'cpu' set iff cpu available to scheduler
|
|
* #endif
|
|
*
|
|
* In either case, NR_CPUS is fixed at compile time, as the static
|
|
* size of these bitmaps. The cpu_possible_map is fixed at boot
|
|
* time, as the set of CPU id's that it is possible might ever
|
|
* be plugged in at anytime during the life of that system boot.
|
|
* The cpu_present_map is dynamic(*), representing which CPUs
|
|
* are currently plugged in. And cpu_online_map is the dynamic
|
|
* subset of cpu_present_map, indicating those CPUs available
|
|
* for scheduling.
|
|
*
|
|
* If HOTPLUG is enabled, then cpu_possible_map is forced to have
|
|
* all NR_CPUS bits set, otherwise it is just the set of CPUs that
|
|
* ACPI reports present at boot.
|
|
*
|
|
* If HOTPLUG is enabled, then cpu_present_map varies dynamically,
|
|
* depending on what ACPI reports as currently plugged in, otherwise
|
|
* cpu_present_map is just a copy of cpu_possible_map.
|
|
*
|
|
* (*) Well, cpu_present_map is dynamic in the hotplug case. If not
|
|
* hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
|
|
*
|
|
* Subtleties:
|
|
* 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
|
|
* assumption that their single CPU is online. The UP
|
|
* cpu_{online,possible,present}_maps are placebos. Changing them
|
|
* will have no useful affect on the following num_*_cpus()
|
|
* and cpu_*() macros in the UP case. This ugliness is a UP
|
|
* optimization - don't waste any instructions or memory references
|
|
* asking if you're online or how many CPUs there are if there is
|
|
* only one CPU.
|
|
* 2) Most SMP arch's #define some of these maps to be some
|
|
* other map specific to that arch. Therefore, the following
|
|
* must be #define macros, not inlines. To see why, examine
|
|
* the assembly code produced by the following. Note that
|
|
* set1() writes phys_x_map, but set2() writes x_map:
|
|
* int x_map, phys_x_map;
|
|
* #define set1(a) x_map = a
|
|
* inline void set2(int a) { x_map = a; }
|
|
* #define x_map phys_x_map
|
|
* main(){ set1(3); set2(5); }
|
|
*/
|
|
|
|
extern cpumask_t cpu_possible_map;
|
|
extern cpumask_t cpu_online_map;
|
|
extern cpumask_t cpu_present_map;
|
|
|
|
#if NR_CPUS > 1
|
|
#define num_online_cpus() cpus_weight_nr(cpu_online_map)
|
|
#define num_possible_cpus() cpus_weight_nr(cpu_possible_map)
|
|
#define num_present_cpus() cpus_weight_nr(cpu_present_map)
|
|
#define cpu_online(cpu) cpu_isset((cpu), cpu_online_map)
|
|
#define cpu_possible(cpu) cpu_isset((cpu), cpu_possible_map)
|
|
#define cpu_present(cpu) cpu_isset((cpu), cpu_present_map)
|
|
#else
|
|
#define num_online_cpus() 1
|
|
#define num_possible_cpus() 1
|
|
#define num_present_cpus() 1
|
|
#define cpu_online(cpu) ((cpu) == 0)
|
|
#define cpu_possible(cpu) ((cpu) == 0)
|
|
#define cpu_present(cpu) ((cpu) == 0)
|
|
#endif
|
|
|
|
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
|
|
|
|
#define for_each_possible_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_possible_map)
|
|
#define for_each_online_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_online_map)
|
|
#define for_each_present_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_present_map)
|
|
|
|
#endif /* __LINUX_CPUMASK_H */
|