Linux kernel mirror (for testing)
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linux
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
9/**
10 * percpu_depopulate - depopulate per-cpu data for given cpu
11 * @__pdata: per-cpu data to depopulate
12 * @cpu: depopulate per-cpu data for this cpu
13 *
14 * Depopulating per-cpu data for a cpu going offline would be a typical
15 * use case. You need to register a cpu hotplug handler for that purpose.
16 */
17void percpu_depopulate(void *__pdata, int cpu)
18{
19 struct percpu_data *pdata = __percpu_disguise(__pdata);
20
21 kfree(pdata->ptrs[cpu]);
22 pdata->ptrs[cpu] = NULL;
23}
24EXPORT_SYMBOL_GPL(percpu_depopulate);
25
26/**
27 * percpu_depopulate_mask - depopulate per-cpu data for some cpu's
28 * @__pdata: per-cpu data to depopulate
29 * @mask: depopulate per-cpu data for cpu's selected through mask bits
30 */
31void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
32{
33 int cpu;
34 for_each_cpu_mask(cpu, *mask)
35 percpu_depopulate(__pdata, cpu);
36}
37EXPORT_SYMBOL_GPL(__percpu_depopulate_mask);
38
39/**
40 * percpu_populate - populate per-cpu data for given cpu
41 * @__pdata: per-cpu data to populate further
42 * @size: size of per-cpu object
43 * @gfp: may sleep or not etc.
44 * @cpu: populate per-data for this cpu
45 *
46 * Populating per-cpu data for a cpu coming online would be a typical
47 * use case. You need to register a cpu hotplug handler for that purpose.
48 * Per-cpu object is populated with zeroed buffer.
49 */
50void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu)
51{
52 struct percpu_data *pdata = __percpu_disguise(__pdata);
53 int node = cpu_to_node(cpu);
54
55 BUG_ON(pdata->ptrs[cpu]);
56 if (node_online(node)) {
57 /* FIXME: kzalloc_node(size, gfp, node) */
58 pdata->ptrs[cpu] = kmalloc_node(size, gfp, node);
59 if (pdata->ptrs[cpu])
60 memset(pdata->ptrs[cpu], 0, size);
61 } else
62 pdata->ptrs[cpu] = kzalloc(size, gfp);
63 return pdata->ptrs[cpu];
64}
65EXPORT_SYMBOL_GPL(percpu_populate);
66
67/**
68 * percpu_populate_mask - populate per-cpu data for more cpu's
69 * @__pdata: per-cpu data to populate further
70 * @size: size of per-cpu object
71 * @gfp: may sleep or not etc.
72 * @mask: populate per-cpu data for cpu's selected through mask bits
73 *
74 * Per-cpu objects are populated with zeroed buffers.
75 */
76int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
77 cpumask_t *mask)
78{
79 cpumask_t populated = CPU_MASK_NONE;
80 int cpu;
81
82 for_each_cpu_mask(cpu, *mask)
83 if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
84 __percpu_depopulate_mask(__pdata, &populated);
85 return -ENOMEM;
86 } else
87 cpu_set(cpu, populated);
88 return 0;
89}
90EXPORT_SYMBOL_GPL(__percpu_populate_mask);
91
92/**
93 * percpu_alloc_mask - initial setup of per-cpu data
94 * @size: size of per-cpu object
95 * @gfp: may sleep or not etc.
96 * @mask: populate per-data for cpu's selected through mask bits
97 *
98 * Populating per-cpu data for all online cpu's would be a typical use case,
99 * which is simplified by the percpu_alloc() wrapper.
100 * Per-cpu objects are populated with zeroed buffers.
101 */
102void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
103{
104 void *pdata = kzalloc(sizeof(struct percpu_data), gfp);
105 void *__pdata = __percpu_disguise(pdata);
106
107 if (unlikely(!pdata))
108 return NULL;
109 if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
110 return __pdata;
111 kfree(pdata);
112 return NULL;
113}
114EXPORT_SYMBOL_GPL(__percpu_alloc_mask);
115
116/**
117 * percpu_free - final cleanup of per-cpu data
118 * @__pdata: object to clean up
119 *
120 * We simply clean up any per-cpu object left. No need for the client to
121 * track and specify through a bis mask which per-cpu objects are to free.
122 */
123void percpu_free(void *__pdata)
124{
125 if (unlikely(!__pdata))
126 return;
127 __percpu_depopulate_mask(__pdata, &cpu_possible_map);
128 kfree(__percpu_disguise(__pdata));
129}
130EXPORT_SYMBOL_GPL(percpu_free);