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

/*
 * linux/mm/allocpercpu.c
 *
 * Separated from slab.c August 11, 2006 Christoph Lameter <clameter@sgi.com>
 */
#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.
 */
void percpu_depopulate(void *__pdata, int cpu)
{
	struct percpu_data *pdata = __percpu_disguise(__pdata);

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

/**
 * 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
 */
void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
{
	int cpu;
	for_each_cpu_mask(cpu, *mask)
		percpu_depopulate(__pdata, cpu);
}
EXPORT_SYMBOL_GPL(__percpu_depopulate_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.
 */
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];
}
EXPORT_SYMBOL_GPL(percpu_populate);

/**
 * 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.
 */
int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
			   cpumask_t *mask)
{
	cpumask_t populated = CPU_MASK_NONE;
	int cpu;

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