[linux-2.6-block.git] / lib / bucket_locks.c

#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
 * indicate the number of elements to allocate in the array. max_size
 * gives the maximum number of elements to allocate. cpu_mult gives
 * the number of locks per CPU to allocate. The size is rounded up
 * to a power of 2 to be suitable as a hash table.
 */

int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
			   size_t max_size, unsigned int cpu_mult, gfp_t gfp)
{
	spinlock_t *tlocks = NULL;
	unsigned int i, size;
#if defined(CONFIG_PROVE_LOCKING)
	unsigned int nr_pcpus = 2;
#else
	unsigned int nr_pcpus = num_possible_cpus();
#endif

	if (cpu_mult) {
		nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
		size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
	} else {
		size = max_size;
	}

	if (sizeof(spinlock_t) != 0) {
		if (gfpflags_allow_blocking(gfp))
			tlocks = kvmalloc(size * sizeof(spinlock_t), gfp);
		else
			tlocks = kmalloc_array(size, sizeof(spinlock_t), gfp);
		if (!tlocks)
			return -ENOMEM;
		for (i = 0; i < size; i++)
			spin_lock_init(&tlocks[i]);
	}

	*locks = tlocks;
	*locks_mask = size - 1;

	return 0;
}
EXPORT_SYMBOL(alloc_bucket_spinlocks);

void free_bucket_spinlocks(spinlock_t *locks)
{
	kvfree(locks);
}
EXPORT_SYMBOL(free_bucket_spinlocks);
Commit	Line	Data
92f36cca TH	1	#include <linux/export.h>
	2	#include <linux/kernel.h>
	3	#include <linux/mm.h>
	4	#include <linux/slab.h>
	5	#include <linux/vmalloc.h>
	6
	7	/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
	8	* indicate the number of elements to allocate in the array. max_size
	9	* gives the maximum number of elements to allocate. cpu_mult gives
	10	* the number of locks per CPU to allocate. The size is rounded up
	11	* to a power of 2 to be suitable as a hash table.
	12	*/
	13
	14	int alloc_bucket_spinlocks(spinlock_t *locks, unsigned int locks_mask,
	15	size_t max_size, unsigned int cpu_mult, gfp_t gfp)
	16	{
	17	spinlock_t *tlocks = NULL;
	18	unsigned int i, size;
	19	#if defined(CONFIG_PROVE_LOCKING)
	20	unsigned int nr_pcpus = 2;
	21	#else
	22	unsigned int nr_pcpus = num_possible_cpus();
	23	#endif
	24
	25	if (cpu_mult) {
	26	nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
	27	size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
	28	} else {
	29	size = max_size;
	30	}
	31
	32	if (sizeof(spinlock_t) != 0) {
	33	if (gfpflags_allow_blocking(gfp))
	34	tlocks = kvmalloc(size * sizeof(spinlock_t), gfp);
	35	else
	36	tlocks = kmalloc_array(size, sizeof(spinlock_t), gfp);
	37	if (!tlocks)
	38	return -ENOMEM;
	39	for (i = 0; i < size; i++)
	40	spin_lock_init(&tlocks[i]);
	41	}
	42
	43	*locks = tlocks;
	44	*locks_mask = size - 1;
	45
	46	return 0;
	47	}
	48	EXPORT_SYMBOL(alloc_bucket_spinlocks);
	49
	50	void free_bucket_spinlocks(spinlock_t *locks)
	51	{
	52	kvfree(locks);
	53	}
	54	EXPORT_SYMBOL(free_bucket_spinlocks);