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-rw-r--r--include/linux/percpu.h47
-rw-r--r--mm/allocpercpu.c32
2 files changed, 41 insertions, 38 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 1fdaee93c04d..d99e24ae1811 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -82,46 +82,43 @@ struct percpu_data {
82 82
83#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) 83#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
84 84
85extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask); 85/*
86extern void percpu_free(void *__pdata); 86 * Use this to get to a cpu's version of the per-cpu object
87 * dynamically allocated. Non-atomic access to the current CPU's
88 * version should probably be combined with get_cpu()/put_cpu().
89 */
90#define per_cpu_ptr(ptr, cpu) \
91({ \
92 struct percpu_data *__p = __percpu_disguise(ptr); \
93 (__typeof__(ptr))__p->ptrs[(cpu)]; \
94})
95
96extern void *__alloc_percpu(size_t size, size_t align);
97extern void free_percpu(void *__pdata);
87 98
88#else /* CONFIG_SMP */ 99#else /* CONFIG_SMP */
89 100
90#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) 101#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
91 102
92static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask) 103static inline void *__alloc_percpu(size_t size, size_t align)
93{ 104{
105 /*
106 * Can't easily make larger alignment work with kmalloc. WARN
107 * on it. Larger alignment should only be used for module
108 * percpu sections on SMP for which this path isn't used.
109 */
110 WARN_ON_ONCE(align > __alignof__(unsigned long long));
94 return kzalloc(size, gfp); 111 return kzalloc(size, gfp);
95} 112}
96 113
97static inline void percpu_free(void *__pdata) 114static inline void free_percpu(void *p)
98{ 115{
99 kfree(__pdata); 116 kfree(p);
100} 117}
101 118
102#endif /* CONFIG_SMP */ 119#endif /* CONFIG_SMP */
103 120
104#define percpu_alloc_mask(size, gfp, mask) \
105 __percpu_alloc_mask((size), (gfp), &(mask))
106
107#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
108
109/* (legacy) interface for use without CPU hotplug handling */
110
111#define __alloc_percpu(size, align) percpu_alloc_mask((size), GFP_KERNEL, \
112 cpu_possible_map)
113#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ 121#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
114 __alignof__(type)) 122 __alignof__(type))
115#define free_percpu(ptr) percpu_free((ptr))
116/*
117 * Use this to get to a cpu's version of the per-cpu object dynamically
118 * allocated. Non-atomic access to the current CPU's version should
119 * probably be combined with get_cpu()/put_cpu().
120 */
121#define per_cpu_ptr(ptr, cpu) \
122({ \
123 struct percpu_data *__p = __percpu_disguise(ptr); \
124 (__typeof__(ptr))__p->ptrs[(cpu)]; \
125})
126 123
127#endif /* __LINUX_PERCPU_H */ 124#endif /* __LINUX_PERCPU_H */
diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index 4297bc41bfd2..3653c570232b 100644
--- a/mm/allocpercpu.c
+++ b/mm/allocpercpu.c
@@ -99,45 +99,51 @@ static int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
99 __percpu_populate_mask((__pdata), (size), (gfp), &(mask)) 99 __percpu_populate_mask((__pdata), (size), (gfp), &(mask))
100 100
101/** 101/**
102 * percpu_alloc_mask - initial setup of per-cpu data 102 * alloc_percpu - initial setup of per-cpu data
103 * @size: size of per-cpu object 103 * @size: size of per-cpu object
104 * @gfp: may sleep or not etc. 104 * @align: alignment
105 * @mask: populate per-data for cpu's selected through mask bits
106 * 105 *
107 * Populating per-cpu data for all online cpu's would be a typical use case, 106 * Allocate dynamic percpu area. Percpu objects are populated with
108 * which is simplified by the percpu_alloc() wrapper. 107 * zeroed buffers.
109 * Per-cpu objects are populated with zeroed buffers.
110 */ 108 */
111void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask) 109void *__alloc_percpu(size_t size, size_t align)
112{ 110{
113 /* 111 /*
114 * We allocate whole cache lines to avoid false sharing 112 * We allocate whole cache lines to avoid false sharing
115 */ 113 */
116 size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size()); 114 size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size());
117 void *pdata = kzalloc(sz, gfp); 115 void *pdata = kzalloc(sz, GFP_KERNEL);
118 void *__pdata = __percpu_disguise(pdata); 116 void *__pdata = __percpu_disguise(pdata);
119 117
118 /*
119 * Can't easily make larger alignment work with kmalloc. WARN
120 * on it. Larger alignment should only be used for module
121 * percpu sections on SMP for which this path isn't used.
122 */
123 WARN_ON_ONCE(align > __alignof__(unsigned long long));
124
120 if (unlikely(!pdata)) 125 if (unlikely(!pdata))
121 return NULL; 126 return NULL;
122 if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask))) 127 if (likely(!__percpu_populate_mask(__pdata, size, GFP_KERNEL,
128 &cpu_possible_map)))
123 return __pdata; 129 return __pdata;
124 kfree(pdata); 130 kfree(pdata);
125 return NULL; 131 return NULL;
126} 132}
127EXPORT_SYMBOL_GPL(__percpu_alloc_mask); 133EXPORT_SYMBOL_GPL(__alloc_percpu);
128 134
129/** 135/**
130 * percpu_free - final cleanup of per-cpu data 136 * free_percpu - final cleanup of per-cpu data
131 * @__pdata: object to clean up 137 * @__pdata: object to clean up
132 * 138 *
133 * We simply clean up any per-cpu object left. No need for the client to 139 * 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. 140 * track and specify through a bis mask which per-cpu objects are to free.
135 */ 141 */
136void percpu_free(void *__pdata) 142void free_percpu(void *__pdata)
137{ 143{
138 if (unlikely(!__pdata)) 144 if (unlikely(!__pdata))
139 return; 145 return;
140 __percpu_depopulate_mask(__pdata, &cpu_possible_map); 146 __percpu_depopulate_mask(__pdata, &cpu_possible_map);
141 kfree(__percpu_disguise(__pdata)); 147 kfree(__percpu_disguise(__pdata));
142} 148}
143EXPORT_SYMBOL_GPL(percpu_free); 149EXPORT_SYMBOL_GPL(free_percpu);