diff options
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 23 | ||||
| -rw-r--r-- | include/linux/cpumask.h | 26 | ||||
| -rw-r--r-- | kernel/cpu.c | 128 |
3 files changed, 43 insertions, 134 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 1cd53dfcd309..76e305e064f9 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -80,26 +80,6 @@ static void __init setup_per_cpu_maps(void) #endif } -#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP -/* - * Replace static cpumask_of_cpu_map in the initdata section, - * with one that's allocated sized by the possible number of cpus. - * - * (requires nr_cpu_ids to be initialized) - */ -static void __init setup_cpumask_of_cpu(void) -{ - int i; - - /* alloc_bootmem zeroes memory */ - cpumask_of_cpu_map = alloc_bootmem_low(sizeof(cpumask_t) * nr_cpu_ids); - for (i = 0; i < nr_cpu_ids; i++) - cpu_set(i, cpumask_of_cpu_map[i]); -} -#else -static inline void setup_cpumask_of_cpu(void) { } -#endif - #ifdef CONFIG_X86_32 /* * Great future not-so-futuristic plan: make i386 and x86_64 do it @@ -199,9 +179,6 @@ void __init setup_per_cpu_areas(void) /* Setup node to cpumask map */ setup_node_to_cpumask_map(); - - /* Setup cpumask_of_cpu map */ - setup_cpumask_of_cpu(); } #endif diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 8fa3b6d4a320..96d0509fb8d8 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -265,10 +265,30 @@ static inline void __cpus_shift_left(cpumask_t *dstp, bitmap_shift_left(dstp->bits, srcp->bits, n, nbits); } +/* + * Special-case data structure for "single bit set only" constant CPU masks. + * + * We pre-generate all the 64 (or 32) possible bit positions, with enough + * padding to the left and the right, and return the constant pointer + * appropriately offset. + */ +extern const unsigned long + cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; + +static inline const cpumask_t *get_cpu_mask(unsigned int cpu) +{ + const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; + p -= cpu / BITS_PER_LONG; + return (const cpumask_t *)p; +} + +/* + * In cases where we take the address of the cpumask immediately, + * gcc optimizes it out (it's a constant) and there's no huge stack + * variable created: + */ +#define cpumask_of_cpu(cpu) ({ *get_cpu_mask(cpu); }) -/* cpumask_of_cpu_map[] is in kernel/cpu.c */ -extern const cpumask_t *cpumask_of_cpu_map; -#define cpumask_of_cpu(cpu) (cpumask_of_cpu_map[cpu]) #define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS) diff --git a/kernel/cpu.c b/kernel/cpu.c index a35d8995dc8c..06a8358bb418 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -462,115 +462,27 @@ out: #endif /* CONFIG_SMP */ -/* 64 bits of zeros, for initializers. */ -#if BITS_PER_LONG == 32 -#define Z64 0, 0 -#else -#define Z64 0 -#endif +/* + * cpu_bit_bitmap[] is a special, "compressed" data structure that + * represents all NR_CPUS bits binary values of 1<<nr. + * + * It is used by cpumask_of_cpu() to get a constant address to a CPU + * mask value that has a single bit set only. + */ -/* Initializer macros. */ -#define CMI0(n) { .bits = { 1UL << (n) } } -#define CMI(n, ...) { .bits = { __VA_ARGS__, 1UL << ((n) % BITS_PER_LONG) } } - -#define CMI8(n, ...) \ - CMI((n), __VA_ARGS__), CMI((n)+1, __VA_ARGS__), \ - CMI((n)+2, __VA_ARGS__), CMI((n)+3, __VA_ARGS__), \ - CMI((n)+4, __VA_ARGS__), CMI((n)+5, __VA_ARGS__), \ - CMI((n)+6, __VA_ARGS__), CMI((n)+7, __VA_ARGS__) - -#if BITS_PER_LONG == 32 -#define CMI64(n, ...) \ - CMI8((n), __VA_ARGS__), CMI8((n)+8, __VA_ARGS__), \ - CMI8((n)+16, __VA_ARGS__), CMI8((n)+24, __VA_ARGS__), \ - CMI8((n)+32, 0, __VA_ARGS__), CMI8((n)+40, 0, __VA_ARGS__), \ - CMI8((n)+48, 0, __VA_ARGS__), CMI8((n)+56, 0, __VA_ARGS__) -#else -#define CMI64(n, ...) \ - CMI8((n), __VA_ARGS__), CMI8((n)+8, __VA_ARGS__), \ - CMI8((n)+16, __VA_ARGS__), CMI8((n)+24, __VA_ARGS__), \ - CMI8((n)+32, __VA_ARGS__), CMI8((n)+40, __VA_ARGS__), \ - CMI8((n)+48, __VA_ARGS__), CMI8((n)+56, __VA_ARGS__) -#endif +/* cpu_bit_bitmap[0] is empty - so we can back into it */ +#define MASK_DECLARE_1(x) [x+1][0] = 1UL << (x) +#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) +#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) +#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) -#define CMI256(n, ...) \ - CMI64((n), __VA_ARGS__), CMI64((n)+64, Z64, __VA_ARGS__), \ - CMI64((n)+128, Z64, Z64, __VA_ARGS__), \ - CMI64((n)+192, Z64, Z64, Z64, __VA_ARGS__) -#define Z256 Z64, Z64, Z64, Z64 - -#define CMI1024(n, ...) \ - CMI256((n), __VA_ARGS__), \ - CMI256((n)+256, Z256, __VA_ARGS__), \ - CMI256((n)+512, Z256, Z256, __VA_ARGS__), \ - CMI256((n)+768, Z256, Z256, Z256, __VA_ARGS__) -#define Z1024 Z256, Z256, Z256, Z256 - -/* We want this statically initialized, just to be safe. We try not - * to waste too much space, either. */ -static const cpumask_t cpumask_map[] -#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP -__initdata -#endif -= { - CMI0(0), CMI0(1), CMI0(2), CMI0(3), -#if NR_CPUS > 4 - CMI0(4), CMI0(5), CMI0(6), CMI0(7), -#endif -#if NR_CPUS > 8 - CMI0(8), CMI0(9), CMI0(10), CMI0(11), - CMI0(12), CMI0(13), CMI0(14), CMI0(15), -#endif -#if NR_CPUS > 16 - CMI0(16), CMI0(17), CMI0(18), CMI0(19), - CMI0(20), CMI0(21), CMI0(22), CMI0(23), - CMI0(24), CMI0(25), CMI0(26), CMI0(27), - CMI0(28), CMI0(29), CMI0(30), CMI0(31), -#endif -#if NR_CPUS > 32 -#if BITS_PER_LONG == 32 - CMI(32, 0), CMI(33, 0), CMI(34, 0), CMI(35, 0), - CMI(36, 0), CMI(37, 0), CMI(38, 0), CMI(39, 0), - CMI(40, 0), CMI(41, 0), CMI(42, 0), CMI(43, 0), - CMI(44, 0), CMI(45, 0), CMI(46, 0), CMI(47, 0), - CMI(48, 0), CMI(49, 0), CMI(50, 0), CMI(51, 0), - CMI(52, 0), CMI(53, 0), CMI(54, 0), CMI(55, 0), - CMI(56, 0), CMI(57, 0), CMI(58, 0), CMI(59, 0), - CMI(60, 0), CMI(61, 0), CMI(62, 0), CMI(63, 0), -#else - CMI0(32), CMI0(33), CMI0(34), CMI0(35), - CMI0(36), CMI0(37), CMI0(38), CMI0(39), - CMI0(40), CMI0(41), CMI0(42), CMI0(43), - CMI0(44), CMI0(45), CMI0(46), CMI0(47), - CMI0(48), CMI0(49), CMI0(50), CMI0(51), - CMI0(52), CMI0(53), CMI0(54), CMI0(55), - CMI0(56), CMI0(57), CMI0(58), CMI0(59), - CMI0(60), CMI0(61), CMI0(62), CMI0(63), -#endif /* BITS_PER_LONG == 64 */ -#endif -#if NR_CPUS > 64 - CMI64(64, Z64), -#endif -#if NR_CPUS > 128 - CMI64(128, Z64, Z64), CMI64(192, Z64, Z64, Z64), -#endif -#if NR_CPUS > 256 - CMI256(256, Z256), -#endif -#if NR_CPUS > 512 - CMI256(512, Z256, Z256), CMI256(768, Z256, Z256, Z256), -#endif -#if NR_CPUS > 1024 - CMI1024(1024, Z1024), -#endif -#if NR_CPUS > 2048 - CMI1024(2048, Z1024, Z1024), CMI1024(3072, Z1024, Z1024, Z1024), -#endif -#if NR_CPUS > 4096 -#error NR_CPUS too big. Fix initializers or set CONFIG_HAVE_CPUMASK_OF_CPU_MAP +const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { + + MASK_DECLARE_8(0), MASK_DECLARE_8(8), + MASK_DECLARE_8(16), MASK_DECLARE_8(24), +#if BITS_PER_LONG > 32 + MASK_DECLARE_8(32), MASK_DECLARE_8(40), + MASK_DECLARE_8(48), MASK_DECLARE_8(56), #endif }; - -const cpumask_t *cpumask_of_cpu_map = cpumask_map; - -EXPORT_SYMBOL_GPL(cpumask_of_cpu_map); +EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |