Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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 pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node);
58 else
59 pdata->ptrs[cpu] = kzalloc(size, gfp);
60 return pdata->ptrs[cpu];
61}
62EXPORT_SYMBOL_GPL(percpu_populate);
63
64/**
65 * percpu_populate_mask - populate per-cpu data for more cpu's
66 * @__pdata: per-cpu data to populate further
67 * @size: size of per-cpu object
68 * @gfp: may sleep or not etc.
69 * @mask: populate per-cpu data for cpu's selected through mask bits
70 *
71 * Per-cpu objects are populated with zeroed buffers.
72 */
73int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
74 cpumask_t *mask)
75{
76 cpumask_t populated = CPU_MASK_NONE;
77 int cpu;
78
79 for_each_cpu_mask(cpu, *mask)
80 if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
81 __percpu_depopulate_mask(__pdata, &populated);
82 return -ENOMEM;
83 } else
84 cpu_set(cpu, populated);
85 return 0;
86}
87EXPORT_SYMBOL_GPL(__percpu_populate_mask);
88
89/**
90 * percpu_alloc_mask - initial setup of per-cpu data
91 * @size: size of per-cpu object
92 * @gfp: may sleep or not etc.
93 * @mask: populate per-data for cpu's selected through mask bits
94 *
95 * Populating per-cpu data for all online cpu's would be a typical use case,
96 * which is simplified by the percpu_alloc() wrapper.
97 * Per-cpu objects are populated with zeroed buffers.
98 */
99void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
100{
101 void *pdata = kzalloc(sizeof(struct percpu_data), gfp);
102 void *__pdata = __percpu_disguise(pdata);
103
104 if (unlikely(!pdata))
105 return NULL;
106 if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
107 return __pdata;
108 kfree(pdata);
109 return NULL;
110}
111EXPORT_SYMBOL_GPL(__percpu_alloc_mask);
112
113/**
114 * percpu_free - final cleanup of per-cpu data
115 * @__pdata: object to clean up
116 *
117 * We simply clean up any per-cpu object left. No need for the client to
118 * track and specify through a bis mask which per-cpu objects are to free.
119 */
120void percpu_free(void *__pdata)
121{
122 if (unlikely(!__pdata))
123 return;
124 __percpu_depopulate_mask(__pdata, &cpu_possible_map);
125 kfree(__percpu_disguise(__pdata));
126}
127EXPORT_SYMBOL_GPL(percpu_free);