[linux-2.6-block.git] / mm / allocpercpu.c

/*
 * linux/mm/allocpercpu.c
 *
 * Separated from slab.c August 11, 2006 Christoph Lameter
 */
#include <linux/mm.h>
#include <linux/module.h>

#ifndef cache_line_size
#define cache_line_size()	L1_CACHE_BYTES
#endif

/**
 * percpu_depopulate - depopulate per-cpu data for given cpu
 * @__pdata: per-cpu data to depopulate
 * @cpu: depopulate per-cpu data for this cpu
 *
 * Depopulating per-cpu data for a cpu going offline would be a typical
 * use case. You need to register a cpu hotplug handler for that purpose.
 */
static void percpu_depopulate(void *__pdata, int cpu)
{
	struct percpu_data *pdata = __percpu_disguise(__pdata);

	kfree(pdata->ptrs[cpu]);
	pdata->ptrs[cpu] = NULL;
}

/**
 * percpu_depopulate_mask - depopulate per-cpu data for some cpu's
 * @__pdata: per-cpu data to depopulate
 * @mask: depopulate per-cpu data for cpu's selected through mask bits
 */
static void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
{
	int cpu;
	for_each_cpu_mask_nr(cpu, *mask)
		percpu_depopulate(__pdata, cpu);
}

#define percpu_depopulate_mask(__pdata, mask) \
	__percpu_depopulate_mask((__pdata), &(mask))

/**
 * percpu_populate - populate per-cpu data for given cpu
 * @__pdata: per-cpu data to populate further
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @cpu: populate per-data for this cpu
 *
 * Populating per-cpu data for a cpu coming online would be a typical
 * use case. You need to register a cpu hotplug handler for that purpose.
 * Per-cpu object is populated with zeroed buffer.
 */
static void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu)
{
	struct percpu_data *pdata = __percpu_disguise(__pdata);
	int node = cpu_to_node(cpu);

	/*
	 * We should make sure each CPU gets private memory.
	 */
	size = roundup(size, cache_line_size());

	BUG_ON(pdata->ptrs[cpu]);
	if (node_online(node))
		pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node);
	else
		pdata->ptrs[cpu] = kzalloc(size, gfp);
	return pdata->ptrs[cpu];
}

/**
 * percpu_populate_mask - populate per-cpu data for more cpu's
 * @__pdata: per-cpu data to populate further
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @mask: populate per-cpu data for cpu's selected through mask bits
 *
 * Per-cpu objects are populated with zeroed buffers.
 */
static int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
				  cpumask_t *mask)
{
	cpumask_t populated;
	int cpu;

	cpus_clear(populated);
	for_each_cpu_mask_nr(cpu, *mask)
		if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
			__percpu_depopulate_mask(__pdata, &populated);
			return -ENOMEM;
		} else
			cpu_set(cpu, populated);
	return 0;
}

#define percpu_populate_mask(__pdata, size, gfp, mask) \
	__percpu_populate_mask((__pdata), (size), (gfp), &(mask))

/**
 * percpu_alloc_mask - initial setup of per-cpu data
 * @size: size of per-cpu object
 * @gfp: may sleep or not etc.
 * @mask: populate per-data for cpu's selected through mask bits
 *
 * Populating per-cpu data for all online cpu's would be a typical use case,
 * which is simplified by the percpu_alloc() wrapper.
 * Per-cpu objects are populated with zeroed buffers.
 */
void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
{
	/*
	 * We allocate whole cache lines to avoid false sharing
	 */
	size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size());
	void *pdata = kzalloc(sz, gfp);
	void *__pdata = __percpu_disguise(pdata);

	if (unlikely(!pdata))
		return NULL;
	if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
		return __pdata;
	kfree(pdata);
	return NULL;
}
EXPORT_SYMBOL_GPL(__percpu_alloc_mask);

/**
 * percpu_free - final cleanup of per-cpu data
 * @__pdata: object to clean up
 *
 * We simply clean up any per-cpu object left. No need for the client to
 * track and specify through a bis mask which per-cpu objects are to free.
 */
void percpu_free(void *__pdata)
{
	if (unlikely(!__pdata))
		return;
	__percpu_depopulate_mask(__pdata, &cpu_possible_map);
	kfree(__percpu_disguise(__pdata));
}
EXPORT_SYMBOL_GPL(percpu_free);
Commit	Line	Data
d00bcc98 CL	1	/*
	2	* linux/mm/allocpercpu.c
	3	*
cde53535	4	* Separated from slab.c August 11, 2006 Christoph Lameter
d00bcc98 CL	5	*/
	6	#include <linux/mm.h>
	7	#include <linux/module.h>
	8
be852795 ED	9	#ifndef cache_line_size
	10	#define cache_line_size() L1_CACHE_BYTES
	11	#endif
	12
d00bcc98 CL	13	/**
	14	* percpu_depopulate - depopulate per-cpu data for given cpu
	15	* @__pdata: per-cpu data to depopulate
	16	* @cpu: depopulate per-cpu data for this cpu
	17	*
	18	* Depopulating per-cpu data for a cpu going offline would be a typical
	19	* use case. You need to register a cpu hotplug handler for that purpose.
	20	*/
9d8fddfb	21	static void percpu_depopulate(void *__pdata, int cpu)
d00bcc98 CL	22	{
d00bcc98 CL	23	struct percpu_data *pdata = __percpu_disguise(__pdata);
a1205868 AS	24
	25	kfree(pdata->ptrs[cpu]);
	26	pdata->ptrs[cpu] = NULL;
d00bcc98	27	}
d00bcc98 CL	28
	29	/**
	30	* percpu_depopulate_mask - depopulate per-cpu data for some cpu's
	31	* @__pdata: per-cpu data to depopulate
	32	* @mask: depopulate per-cpu data for cpu's selected through mask bits
	33	*/
9d8fddfb	34	static void __percpu_depopulate_mask(void __pdata, cpumask_t mask)
d00bcc98 CL	35	{
d00bcc98 CL	36	int cpu;
6d6a4360	37	for_each_cpu_mask_nr(cpu, *mask)
d00bcc98 CL	38	percpu_depopulate(__pdata, cpu);
d00bcc98 CL	39	}
9d8fddfb AB	40
	41	#define percpu_depopulate_mask(__pdata, mask) \
	42	__percpu_depopulate_mask((__pdata), &(mask))
d00bcc98 CL	43
	44	/**
	45	* percpu_populate - populate per-cpu data for given cpu
	46	* @__pdata: per-cpu data to populate further
	47	* @size: size of per-cpu object
	48	* @gfp: may sleep or not etc.
	49	* @cpu: populate per-data for this cpu
	50	*
	51	* Populating per-cpu data for a cpu coming online would be a typical
	52	* use case. You need to register a cpu hotplug handler for that purpose.
	53	* Per-cpu object is populated with zeroed buffer.
	54	*/
9d8fddfb	55	static void percpu_populate(void __pdata, size_t size, gfp_t gfp, int cpu)
d00bcc98 CL	56	{
	57	struct percpu_data *pdata = __percpu_disguise(__pdata);
	58	int node = cpu_to_node(cpu);
	59
be852795 ED	60	/*
	61	* We should make sure each CPU gets private memory.
	62	*/
	63	size = roundup(size, cache_line_size());
	64
d00bcc98	65	BUG_ON(pdata->ptrs[cpu]);
94f6030c CL	66	if (node_online(node))
	67	pdata->ptrs[cpu] = kmalloc_node(size, gfp\|__GFP_ZERO, node);
	68	else
d00bcc98 CL	69	pdata->ptrs[cpu] = kzalloc(size, gfp);
	70	return pdata->ptrs[cpu];
	71	}
d00bcc98 CL	72
	73	/**
	74	* percpu_populate_mask - populate per-cpu data for more cpu's
	75	* @__pdata: per-cpu data to populate further
	76	* @size: size of per-cpu object
	77	* @gfp: may sleep or not etc.
	78	* @mask: populate per-cpu data for cpu's selected through mask bits
	79	*
	80	* Per-cpu objects are populated with zeroed buffers.
	81	*/
9d8fddfb AB	82	static int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
9d8fddfb AB	83	cpumask_t *mask)
d00bcc98	84	{
d366f8cb	85	cpumask_t populated;
d00bcc98 CL	86	int cpu;
d00bcc98 CL	87
d366f8cb	88	cpus_clear(populated);
6d6a4360	89	for_each_cpu_mask_nr(cpu, *mask)
d00bcc98 CL	90	if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
	91	__percpu_depopulate_mask(__pdata, &populated);
	92	return -ENOMEM;
	93	} else
	94	cpu_set(cpu, populated);
	95	return 0;
	96	}
9d8fddfb AB	97
	98	#define percpu_populate_mask(__pdata, size, gfp, mask) \
	99	__percpu_populate_mask((__pdata), (size), (gfp), &(mask))
d00bcc98 CL	100
	101	/**
	102	* percpu_alloc_mask - initial setup of per-cpu data
	103	* @size: size of per-cpu object
	104	* @gfp: may sleep or not etc.
	105	* @mask: populate per-data for cpu's selected through mask bits
	106	*
	107	* Populating per-cpu data for all online cpu's would be a typical use case,
	108	* which is simplified by the percpu_alloc() wrapper.
	109	* Per-cpu objects are populated with zeroed buffers.
	110	*/
	111	void __percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t mask)
	112	{
be852795 ED	113	/*
	114	* We allocate whole cache lines to avoid false sharing
	115	*/
	116	size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size());
	117	void *pdata = kzalloc(sz, gfp);
d00bcc98 CL	118	void *__pdata = __percpu_disguise(pdata);
	119
	120	if (unlikely(!pdata))
	121	return NULL;
	122	if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
	123	return __pdata;
	124	kfree(pdata);
	125	return NULL;
	126	}
	127	EXPORT_SYMBOL_GPL(__percpu_alloc_mask);
	128
	129	/**
	130	* percpu_free - final cleanup of per-cpu data
	131	* @__pdata: object to clean up
	132	*
	133	* We simply clean up any per-cpu object left. No need for the client to
	134	* track and specify through a bis mask which per-cpu objects are to free.
	135	*/
	136	void percpu_free(void *__pdata)
	137	{
a1205868 AS	138	if (unlikely(!__pdata))
a1205868 AS	139	return;
d00bcc98 CL	140	__percpu_depopulate_mask(__pdata, &cpu_possible_map);
	141	kfree(__percpu_disguise(__pdata));
	142	}
	143	EXPORT_SYMBOL_GPL(percpu_free);