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-rw-r--r--include/linux/cpumask.h172
1 files changed, 133 insertions, 39 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index c24875bd9c5..1b5c98e7fef 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -17,6 +17,20 @@
* 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
@@ -38,18 +52,60 @@
* 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
*
+ * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t
+ * variables, and CPUMASK_PTR provides pointers to each field.
+ *
+ * The structure should be defined something like this:
+ * struct my_cpumasks {
+ * cpumask_t mask1;
+ * cpumask_t mask2;
+ * };
+ *
+ * Usage is then:
+ * CPUMASK_ALLOC(my_cpumasks);
+ * CPUMASK_PTR(mask1, my_cpumasks);
+ * CPUMASK_PTR(mask2, my_cpumasks);
+ *
+ * --- DO NOT reference cpumask_t pointers until this check ---
+ * if (my_cpumasks == NULL)
+ * "kmalloc failed"...
+ *
+ * References are now pointers to the cpumask_t variables (*mask1, ...)
+ *
+ *if NR_CPUS > BITS_PER_LONG
+ * CPUMASK_ALLOC(m) Declares and allocates struct m *m =
+ * kmalloc(sizeof(*m), GFP_KERNEL)
+ * CPUMASK_FREE(m) Macro for kfree(m)
+ *else
+ * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m
+ * CPUMASK_FREE(m) Nop
+ *endif
+ * CPUMASK_PTR(v, m) Declares cpumask_t *v = &(m->v)
+ * ------------------------------------------------------------------------
+ *
* 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
@@ -59,7 +115,8 @@
* 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
+ * 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
@@ -216,23 +273,19 @@ static inline void __cpus_shift_left(cpumask_t *dstp,
bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
}
-#ifdef CONFIG_SMP
-int __first_cpu(const cpumask_t *srcp);
-#define first_cpu(src) __first_cpu(&(src))
-int __next_cpu(int n, const cpumask_t *srcp);
-#define next_cpu(n, src) __next_cpu((n), &(src))
-#else
-#define first_cpu(src) ({ (void)(src); 0; })
-#define next_cpu(n, src) ({ (void)(src); 1; })
-#endif
#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(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); \
@@ -240,8 +293,16 @@ extern cpumask_t *cpumask_of_cpu_map;
cpus_clear(m); \
cpu_set((cpu), m); \
} \
- &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)
@@ -281,6 +342,15 @@ extern cpumask_t cpu_mask_all;
#define cpus_addr(src) ((src).bits)
+#if NR_CPUS > BITS_PER_LONG
+#define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL)
+#define CPUMASK_FREE(m) kfree(m)
+#else
+#define CPUMASK_ALLOC(m) struct m _m, *m = &_m
+#define CPUMASK_FREE(m)
+#endif
+#define CPUMASK_PTR(v, m) cpumask_t *v = &(m->v)
+
#define cpumask_scnprintf(buf, len, src) \
__cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
static inline int __cpumask_scnprintf(char *buf, int len,
@@ -343,29 +413,59 @@ static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
bitmap_fold(dstp->bits, origp->bits, sz, nbits);
}
-#if NR_CPUS > 1
-#define for_each_cpu_mask(cpu, mask) \
- for ((cpu) = first_cpu(mask); \
- (cpu) < NR_CPUS; \
- (cpu) = next_cpu((cpu), (mask)))
-#else /* NR_CPUS == 1 */
-#define for_each_cpu_mask(cpu, mask) \
+#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)
-#endif /* NR_CPUS */
+
+#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
+ * possible, present, active 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
+ * cpu_active_map - has bit 'cpu' set iff cpu available to migration
* #else
* cpu_possible_map - has bit 'cpu' set iff cpu is populated
* cpu_present_map - copy of cpu_possible_map
@@ -416,14 +516,16 @@ static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
extern cpumask_t cpu_possible_map;
extern cpumask_t cpu_online_map;
extern cpumask_t cpu_present_map;
+extern cpumask_t cpu_active_map;
#if NR_CPUS > 1
-#define num_online_cpus() cpus_weight(cpu_online_map)
-#define num_possible_cpus() cpus_weight(cpu_possible_map)
-#define num_present_cpus() cpus_weight(cpu_present_map)
+#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)
+#define cpu_active(cpu) cpu_isset((cpu), cpu_active_map)
#else
#define num_online_cpus() 1
#define num_possible_cpus() 1
@@ -431,21 +533,13 @@ extern cpumask_t cpu_present_map;
#define cpu_online(cpu) ((cpu) == 0)
#define cpu_possible(cpu) ((cpu) == 0)
#define cpu_present(cpu) ((cpu) == 0)
+#define cpu_active(cpu) ((cpu) == 0)
#endif
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
-#ifdef CONFIG_SMP
-extern int nr_cpu_ids;
-#define any_online_cpu(mask) __any_online_cpu(&(mask))
-int __any_online_cpu(const cpumask_t *mask);
-#else
-#define nr_cpu_ids 1
-#define any_online_cpu(mask) 0
-#endif
-
-#define for_each_possible_cpu(cpu) for_each_cpu_mask((cpu), cpu_possible_map)
-#define for_each_online_cpu(cpu) for_each_cpu_mask((cpu), cpu_online_map)
-#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
+#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 */