blob: b0012e27fea8796da01cfb2172d1d5930c60d22f [file] [log] [blame]
Christoph Lameterd00bcc92006-09-25 23:31:50 -07001/*
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
Eric Dumazetbe852792008-03-04 14:28:35 -08009#ifndef cache_line_size
10#define cache_line_size() L1_CACHE_BYTES
11#endif
12
Christoph Lameterd00bcc92006-09-25 23:31:50 -070013/**
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 */
21void percpu_depopulate(void *__pdata, int cpu)
22{
23 struct percpu_data *pdata = __percpu_disguise(__pdata);
Alan Sterna1205862006-12-06 20:32:37 -080024
25 kfree(pdata->ptrs[cpu]);
26 pdata->ptrs[cpu] = NULL;
Christoph Lameterd00bcc92006-09-25 23:31:50 -070027}
28EXPORT_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 */
35void __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}
41EXPORT_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 */
54void *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
Eric Dumazetbe852792008-03-04 14:28:35 -080059 /*
60 * We should make sure each CPU gets private memory.
61 */
62 size = roundup(size, cache_line_size());
63
Christoph Lameterd00bcc92006-09-25 23:31:50 -070064 BUG_ON(pdata->ptrs[cpu]);
Christoph Lameter94f60302007-07-17 04:03:29 -070065 if (node_online(node))
66 pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node);
67 else
Christoph Lameterd00bcc92006-09-25 23:31:50 -070068 pdata->ptrs[cpu] = kzalloc(size, gfp);
69 return pdata->ptrs[cpu];
70}
71EXPORT_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 */
82int __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}
96EXPORT_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 */
108void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
109{
Eric Dumazetbe852792008-03-04 14:28:35 -0800110 /*
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);
Christoph Lameterd00bcc92006-09-25 23:31:50 -0700115 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}
124EXPORT_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 */
133void percpu_free(void *__pdata)
134{
Alan Sterna1205862006-12-06 20:32:37 -0800135 if (unlikely(!__pdata))
136 return;
Christoph Lameterd00bcc92006-09-25 23:31:50 -0700137 __percpu_depopulate_mask(__pdata, &cpu_possible_map);
138 kfree(__percpu_disguise(__pdata));
139}
140EXPORT_SYMBOL_GPL(percpu_free);