From: Paul Jackson Major rewrite of cpumask to use a single implementation, as a struct-wrapped bitmap. This patch leaves some 26 include/asm-*/cpumask*.h header files orphaned - to be removed next patch. Some nine cpumask macros for const variants and to coerce and promote between an unsigned long and a cpumask are obsolete. Simple emulation wrappers are provided in this patch for these obsolete macros, which can be removed once each of the 3 archs (i386, ppc64, x86_64) using them are recoded in follow-on patches to not need them. The CPU_MASK_ALL macro now avoids leaving possible garbage one bits in any unused portion of the high word. An inproved comment lists all available operators, for convenient browsing. Signed-off-by: Paul Jackson Signed-off-by: Andrew Morton --- 25-akpm/arch/sparc64/kernel/irq.c | 6 25-akpm/include/linux/cpumask.h | 394 ++++++++++++++++++++++++++++++++++---- 25-akpm/kernel/rcupdate.c | 7 25-akpm/kernel/sched.c | 5 4 files changed, 371 insertions(+), 41 deletions(-) diff -puN arch/sparc64/kernel/irq.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based arch/sparc64/kernel/irq.c --- 25/arch/sparc64/kernel/irq.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based 2004-06-17 22:36:03.825951040 -0700 +++ 25-akpm/arch/sparc64/kernel/irq.c 2004-06-17 22:36:03.838949064 -0700 @@ -691,9 +691,10 @@ static inline void redirect_intr(int cpu * Just Do It. */ struct irqaction *ap = bp->irq_info; - cpumask_t cpu_mask = get_smpaff_in_irqaction(ap); + cpumask_t cpu_mask; unsigned int buddy, ticks; + cpus_addr(cpu_mask)[0] = get_smpaff_in_irqaction(ap); cpus_and(cpu_mask, cpu_mask, cpu_online_map); if (cpus_empty(cpu_mask)) cpu_mask = cpu_online_map; @@ -1210,9 +1211,10 @@ static int irq_affinity_read_proc (char { struct ino_bucket *bp = ivector_table + (long)data; struct irqaction *ap = bp->irq_info; - cpumask_t mask = get_smpaff_in_irqaction(ap); + cpumask_t mask; int len; + cpus_addr(mask)[0] = get_smpaff_in_irqaction(ap); if (cpus_empty(mask)) mask = cpu_online_map; diff -puN include/linux/cpumask.h~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based include/linux/cpumask.h --- 25/include/linux/cpumask.h~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based 2004-06-17 22:36:03.827950736 -0700 +++ 25-akpm/include/linux/cpumask.h 2004-06-17 22:36:03.884942072 -0700 @@ -1,53 +1,379 @@ #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(), + * see bitmap_scnprintf() and bitmap_parse() in lib/bitmap.c. + * + * 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 + * + * 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 + * + * cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set + * 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(ubuf, ulen, mask) Parse ascii string as cpumask + * + * int num_online_cpus() Number of online CPUs + * int num_possible_cpus() Number of all possible CPUs + * int cpu_online(cpu) Is some cpu online? + * int cpu_possible(cpu) Is some cpu possible? + * void cpu_set_online(cpu) set cpu in cpu_online_map + * void cpu_set_offline(cpu) clear cpu in cpu_online_map + * int any_online_cpu(mask) First online cpu in mask + * + * for_each_cpu_mask(cpu, mask) for-loop cpu over mask + * for_each_cpu(cpu) for-loop cpu over cpu_possible_map + * for_each_online_cpu(cpu) for-loop cpu over cpu_online_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 #include -#include #include -#ifdef CONFIG_SMP - -extern cpumask_t cpu_online_map; -extern cpumask_t cpu_possible_map; - -#define num_online_cpus() cpus_weight(cpu_online_map) -#define num_possible_cpus() cpus_weight(cpu_possible_map) - -#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map) -#define cpu_possible(cpu) cpu_isset(cpu, cpu_possible_map) +typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; +extern cpumask_t _unused_cpumask_arg_; -#define for_each_cpu_mask(cpu, mask) \ - for (cpu = first_cpu_const(mk_cpumask_const(mask)); \ - cpu < NR_CPUS; \ - cpu = next_cpu_const(cpu, mk_cpumask_const(mask))) +#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, cpumask_t *src1p, + 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, cpumask_t *src1p, + 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, cpumask_t *src1p, + 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, cpumask_t *src1p, + 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, + 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(cpumask_t *src1p, + 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(cpumask_t *src1p, + 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(cpumask_t *src1p, + 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(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(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(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, + 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, + cpumask_t *srcp, int n, int nbits) +{ + bitmap_shift_left(dstp->bits, srcp->bits, n, nbits); +} + +#define first_cpu(src) __first_cpu(&(src), NR_CPUS) +static inline int __first_cpu(cpumask_t *srcp, int nbits) +{ + return find_first_bit(srcp->bits, nbits); +} + +#define next_cpu(n, src) __next_cpu((n), &(src), NR_CPUS) +static inline int __next_cpu(int n, cpumask_t *srcp, int nbits) +{ + return find_next_bit(srcp->bits, nbits, n+1); +} + +#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 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 for_each_cpu(cpu) for_each_cpu_mask(cpu, cpu_possible_map) -#define for_each_online_cpu(cpu) for_each_cpu_mask(cpu, cpu_online_map) #else -#define cpu_online_map cpumask_of_cpu(0) -#define cpu_possible_map cpumask_of_cpu(0) -#define num_online_cpus() 1 -#define num_possible_cpus() 1 +#define CPU_MASK_ALL \ +((cpumask_t) { { \ + [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ + [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \ +} }) -#define cpu_online(cpu) ({ BUG_ON((cpu) != 0); 1; }) -#define cpu_possible(cpu) ({ BUG_ON((cpu) != 0); 1; }) - -#define for_each_cpu_mask(cpu, mask) for (cpu = 0; cpu < 1; cpu++) -#define for_each_cpu(cpu) for (cpu = 0; cpu < 1; cpu++) -#define for_each_online_cpu(cpu) for (cpu = 0; cpu < 1; cpu++) #endif +#define CPU_MASK_NONE \ +{ { \ + [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ +} } + +#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, + cpumask_t *srcp, int nbits) +{ + return bitmap_scnprintf(buf, len, srcp->bits, nbits); +} + +#define cpumask_parse(ubuf, ulen, src) \ + __cpumask_parse((ubuf), (ulen), &(src), NR_CPUS) +static inline int __cpumask_parse(const char __user *buf, int len, + cpumask_t *srcp, int nbits) +{ + return bitmap_parse(buf, len, srcp->bits, 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) for ((cpu) = 0; (cpu) < 1; (cpu)++) +#endif /* NR_CPUS */ + +/* + * 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 - all NR_CPUS bits set + * 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; -#define num_present_cpus() cpus_weight(cpu_present_map) -#define cpu_present(cpu) cpu_isset(cpu, cpu_present_map) -#define for_each_present_cpu(cpu) for_each_cpu_mask(cpu, cpu_present_map) -#define cpumask_scnprintf(buf, buflen, map) \ - bitmap_scnprintf(buf, buflen, cpus_addr(map), NR_CPUS) +#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 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 cpumask_parse(buf, buflen, map) \ - bitmap_parse(buf, buflen, cpus_addr(map), NR_CPUS) +#define any_online_cpu(mask) \ +({ \ + int cpu; \ + for_each_cpu_mask(cpu, (mask)) \ + if (cpu_online(cpu)) \ + break; \ + cpu; \ +}) + +#define for_each_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) + +/* Begin obsolete cpumask operator emulation */ +#define cpu_isset_const(a,b) cpu_isset(a,b) +#define cpumask_const_t cpumask_t +#define cpus_coerce(m) (cpus_addr(m)[0]) +#define cpus_coerce_const cpus_coerce +#define cpus_promote(x) ({ cpumask_t m; m.bits[0] = x; m; }) +#define cpus_weight_const cpus_weight +#define first_cpu_const first_cpu +#define mk_cpumask_const(x) x +#define next_cpu_const next_cpu +/* End of obsolete cpumask operator emulation */ #endif /* __LINUX_CPUMASK_H */ diff -puN kernel/rcupdate.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based kernel/rcupdate.c --- 25/kernel/rcupdate.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based 2004-06-17 22:36:03.830950280 -0700 +++ 25-akpm/kernel/rcupdate.c 2004-06-17 22:36:03.886941768 -0700 @@ -128,17 +128,14 @@ static void rcu_do_batch(struct rcu_head */ static void rcu_start_batch(int next_pending) { - cpumask_t active; - if (next_pending) rcu_ctrlblk.next_pending = 1; if (rcu_ctrlblk.next_pending && rcu_ctrlblk.completed == rcu_ctrlblk.cur) { /* Can't change, since spin lock held. */ - active = nohz_cpu_mask; - cpus_complement(active); - cpus_and(rcu_state.rcu_cpu_mask, cpu_online_map, active); + cpus_andnot(rcu_state.rcu_cpu_mask, cpu_online_map, + nohz_cpu_mask); write_seqcount_begin(&rcu_ctrlblk.lock); rcu_ctrlblk.next_pending = 0; rcu_ctrlblk.cur++; diff -puN kernel/sched.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based kernel/sched.c --- 25/kernel/sched.c~cpumask-5-10-rewrite-cpumaskh-single-bitmap-based 2004-06-17 22:36:03.833949824 -0700 +++ 25-akpm/kernel/sched.c 2004-06-17 22:36:03.891941008 -0700 @@ -3126,6 +3126,11 @@ out_unlock: cpumask_t cpu_present_map; EXPORT_SYMBOL(cpu_present_map); +#ifndef CONFIG_SMP +cpumask_t cpu_online_map = CPU_MASK_ALL; +cpumask_t cpu_possible_map = CPU_MASK_ALL; +#endif + /** * sys_sched_getaffinity - get the cpu affinity of a process * @pid: pid of the process _