// SPDX-License-Identifier: GPL-2.0
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <pthread.h>
#include <unistd.h>
#include <assert.h>
#include <linux/gfp.h>
#include <linux/poison.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <urcu/uatomic.h>
int nr_allocated;
int preempt_count;
int test_verbose;
struct kmem_cache {
pthread_mutex_t lock;
unsigned int size;
unsigned int align;
int nr_objs;
void *objs;
void (*ctor)(void *);
unsigned int non_kernel;
unsigned long nr_allocated;
unsigned long nr_tallocated;
};
void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val)
{
cachep->non_kernel = val;
}
unsigned long kmem_cache_get_alloc(struct kmem_cache *cachep)
{
return cachep->size * cachep->nr_allocated;
}
unsigned long kmem_cache_nr_allocated(struct kmem_cache *cachep)
{
return cachep->nr_allocated;
}
unsigned long kmem_cache_nr_tallocated(struct kmem_cache *cachep)
{
return cachep->nr_tallocated;
}
void kmem_cache_zero_nr_tallocated(struct kmem_cache *cachep)
{
cachep->nr_tallocated = 0;
}
void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
int gfp)
{
void *p;
if (!(gfp & __GFP_DIRECT_RECLAIM)) {
if (!cachep->non_kernel)
return NULL;
cachep->non_kernel--;
}
pthread_mutex_lock(&cachep->lock);
if (cachep->nr_objs) {
struct radix_tree_node *node = cachep->objs;
cachep->nr_objs--;
cachep->objs = node->parent;
pthread_mutex_unlock(&cachep->lock);
node->parent = NULL;
p = node;
} else {
pthread_mutex_unlock(&cachep->lock);
if (cachep->align)
posix_memalign(&p, cachep->align, cachep->size);
else
p = malloc(cachep->size);
if (cachep->ctor)
cachep->ctor(p);
else if (gfp & __GFP_ZERO)
memset(p, 0, cachep->size);
}
uatomic_inc(&cachep->nr_allocated);
uatomic_inc(&nr_allocated);
uatomic_inc(&cachep->nr_tallocated);
if (kmalloc_verbose)
printf("Allocating %p from slab\n", p);
return p;
}
void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
{
assert(objp);
if (cachep->nr_objs > 10 || cachep->align) {
memset(objp, POISON_FREE, cachep->size);
free(objp);
} else {
struct radix_tree_node *node = objp;
cachep->nr_objs++;
node->parent = cachep->objs;
cachep->objs = node;
}
}
void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
{
uatomic_dec(&nr_allocated);
uatomic_dec(&cachep->nr_allocated);
if (kmalloc_verbose)
printf("Freeing %p to slab\n", objp);
__kmem_cache_free_locked(cachep, objp);
}
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
{
pthread_mutex_lock(&cachep->lock);
kmem_cache_free_locked(cachep, objp);
pthread_mutex_unlock(&cachep->lock);
}
void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list)
{
if (kmalloc_verbose)
pr_debug("Bulk free %p[0-%lu]\n", list, size - 1);
pthread_mutex_lock(&cachep->lock);
for (int i = 0; i < size; i++)
kmem_cache_free_locked(cachep, list[i]);
pthread_mutex_unlock(&cachep->lock);
}
void kmem_cache_shrink(struct kmem_cache *cachep)
{
}
int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
void **p)
{
size_t i;
if (kmalloc_verbose)
pr_debug("Bulk alloc %lu\n", size);
pthread_mutex_lock(&cachep->lock);
if (cachep->nr_objs >= size) {
struct radix_tree_node *node;
for (i = 0; i < size; i++) {
if (!(gfp & __GFP_DIRECT_RECLAIM)) {
if (!cachep->non_kernel)
break;
cachep->non_kernel--;
}
node = cachep->objs;
cachep->nr_objs--;
cachep->objs = node->parent;
p[i] = node;
node->parent = NULL;
}
pthread_mutex_unlock(&cachep->lock);
} else {
pthread_mutex_unlock(&cachep->lock);
for (i = 0; i < size; i++) {
if (!(gfp & __GFP_DIRECT_RECLAIM)) {
if (!cachep->non_kernel)
break;
cachep->non_kernel--;
}
if (cachep->align) {
posix_memalign(&p[i], cachep->align,
cachep->size);
} else {
p[i] = malloc(cachep->size);
if (!p[i])
break;
}
if (cachep->ctor)
cachep->ctor(p[i]);
else if (gfp & __GFP_ZERO)
memset(p[i], 0, cachep->size);
}
}
if (i < size) {
size = i;
pthread_mutex_lock(&cachep->lock);
for (i = 0; i < size; i++)
__kmem_cache_free_locked(cachep, p[i]);
pthread_mutex_unlock(&cachep->lock);
return 0;
}
for (i = 0; i < size; i++) {
uatomic_inc(&nr_allocated);
uatomic_inc(&cachep->nr_allocated);
uatomic_inc(&cachep->nr_tallocated);
if (kmalloc_verbose)
printf("Allocating %p from slab\n", p[i]);
}
return size;
}
struct kmem_cache *
kmem_cache_create(const char *name, unsigned int size, unsigned int align,
unsigned int flags, void (*ctor)(void *))
{
struct kmem_cache *ret = malloc(sizeof(*ret));
pthread_mutex_init(&ret->lock, NULL);
ret->size = size;
ret->align = align;
ret->nr_objs = 0;
ret->nr_allocated = 0;
ret->nr_tallocated = 0;
ret->objs = NULL;
ret->ctor = ctor;
ret->non_kernel = 0;
return ret;
}
/*
* Test the test infrastructure for kem_cache_alloc/free and bulk counterparts.
*/
void test_kmem_cache_bulk(void)
{
int i;
void *list[12];
static struct kmem_cache *test_cache, *test_cache2;
/*
* Testing the bulk allocators without aligned kmem_cache to force the
* bulk alloc/free to reuse
*/
test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL);
for (i = 0; i < 5; i++)
list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
for (i = 0; i < 5; i++)
kmem_cache_free(test_cache, list[i]);
assert(test_cache->nr_objs == 5);
kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list);
kmem_cache_free_bulk(test_cache, 5, list);
for (i = 0; i < 12 ; i++)
list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
for (i = 0; i < 12; i++)
kmem_cache_free(test_cache, list[i]);
/* The last free will not be kept around */
assert(test_cache->nr_objs == 11);
/* Aligned caches will immediately free */
test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL);
kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list);
kmem_cache_free_bulk(test_cache2, 10, list);
assert(!test_cache2->nr_objs);
}
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