Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#include <stdlib.h>
2#include <string.h>
3#include <malloc.h>
4#include <pthread.h>
5#include <unistd.h>
6#include <assert.h>
7
8#include <linux/gfp.h>
9#include <linux/poison.h>
10#include <linux/slab.h>
11#include <linux/radix-tree.h>
12#include <urcu/uatomic.h>
13
14int nr_allocated;
15int preempt_count;
16int kmalloc_verbose;
17int test_verbose;
18
19struct kmem_cache {
20 pthread_mutex_t lock;
21 int size;
22 int nr_objs;
23 void *objs;
24 void (*ctor)(void *);
25};
26
27void *kmem_cache_alloc(struct kmem_cache *cachep, int flags)
28{
29 struct radix_tree_node *node;
30
31 if (flags & __GFP_NOWARN)
32 return NULL;
33
34 pthread_mutex_lock(&cachep->lock);
35 if (cachep->nr_objs) {
36 cachep->nr_objs--;
37 node = cachep->objs;
38 cachep->objs = node->parent;
39 pthread_mutex_unlock(&cachep->lock);
40 node->parent = NULL;
41 } else {
42 pthread_mutex_unlock(&cachep->lock);
43 node = malloc(cachep->size);
44 if (cachep->ctor)
45 cachep->ctor(node);
46 }
47
48 uatomic_inc(&nr_allocated);
49 if (kmalloc_verbose)
50 printf("Allocating %p from slab\n", node);
51 return node;
52}
53
54void kmem_cache_free(struct kmem_cache *cachep, void *objp)
55{
56 assert(objp);
57 uatomic_dec(&nr_allocated);
58 if (kmalloc_verbose)
59 printf("Freeing %p to slab\n", objp);
60 pthread_mutex_lock(&cachep->lock);
61 if (cachep->nr_objs > 10) {
62 memset(objp, POISON_FREE, cachep->size);
63 free(objp);
64 } else {
65 struct radix_tree_node *node = objp;
66 cachep->nr_objs++;
67 node->parent = cachep->objs;
68 cachep->objs = node;
69 }
70 pthread_mutex_unlock(&cachep->lock);
71}
72
73void *kmalloc(size_t size, gfp_t gfp)
74{
75 void *ret = malloc(size);
76 uatomic_inc(&nr_allocated);
77 if (kmalloc_verbose)
78 printf("Allocating %p from malloc\n", ret);
79 return ret;
80}
81
82void kfree(void *p)
83{
84 if (!p)
85 return;
86 uatomic_dec(&nr_allocated);
87 if (kmalloc_verbose)
88 printf("Freeing %p to malloc\n", p);
89 free(p);
90}
91
92struct kmem_cache *
93kmem_cache_create(const char *name, size_t size, size_t offset,
94 unsigned long flags, void (*ctor)(void *))
95{
96 struct kmem_cache *ret = malloc(sizeof(*ret));
97
98 pthread_mutex_init(&ret->lock, NULL);
99 ret->size = size;
100 ret->nr_objs = 0;
101 ret->objs = NULL;
102 ret->ctor = ctor;
103 return ret;
104}