105 lines
2.1 KiB
C
105 lines
2.1 KiB
C
#include <stdlib.h>
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#include <string.h>
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#include <malloc.h>
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#include <pthread.h>
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#include <unistd.h>
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#include <assert.h>
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#include <linux/gfp.h>
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#include <linux/poison.h>
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#include <linux/slab.h>
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#include <linux/radix-tree.h>
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#include <urcu/uatomic.h>
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int nr_allocated;
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int preempt_count;
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int kmalloc_verbose;
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int test_verbose;
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struct kmem_cache {
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pthread_mutex_t lock;
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int size;
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int nr_objs;
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void *objs;
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void (*ctor)(void *);
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};
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void *kmem_cache_alloc(struct kmem_cache *cachep, int flags)
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{
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struct radix_tree_node *node;
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if (flags & __GFP_NOWARN)
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return NULL;
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pthread_mutex_lock(&cachep->lock);
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if (cachep->nr_objs) {
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cachep->nr_objs--;
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node = cachep->objs;
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cachep->objs = node->parent;
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pthread_mutex_unlock(&cachep->lock);
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node->parent = NULL;
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} else {
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pthread_mutex_unlock(&cachep->lock);
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node = malloc(cachep->size);
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if (cachep->ctor)
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cachep->ctor(node);
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}
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uatomic_inc(&nr_allocated);
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if (kmalloc_verbose)
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printf("Allocating %p from slab\n", node);
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return node;
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}
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void kmem_cache_free(struct kmem_cache *cachep, void *objp)
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{
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assert(objp);
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uatomic_dec(&nr_allocated);
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if (kmalloc_verbose)
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printf("Freeing %p to slab\n", objp);
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pthread_mutex_lock(&cachep->lock);
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if (cachep->nr_objs > 10) {
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memset(objp, POISON_FREE, cachep->size);
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free(objp);
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} else {
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struct radix_tree_node *node = objp;
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cachep->nr_objs++;
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node->parent = cachep->objs;
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cachep->objs = node;
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}
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pthread_mutex_unlock(&cachep->lock);
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}
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void *kmalloc(size_t size, gfp_t gfp)
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{
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void *ret = malloc(size);
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uatomic_inc(&nr_allocated);
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if (kmalloc_verbose)
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printf("Allocating %p from malloc\n", ret);
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return ret;
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}
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void kfree(void *p)
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{
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if (!p)
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return;
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uatomic_dec(&nr_allocated);
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if (kmalloc_verbose)
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printf("Freeing %p to malloc\n", p);
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free(p);
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}
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struct kmem_cache *
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kmem_cache_create(const char *name, size_t size, size_t offset,
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unsigned long flags, void (*ctor)(void *))
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{
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struct kmem_cache *ret = malloc(sizeof(*ret));
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pthread_mutex_init(&ret->lock, NULL);
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ret->size = size;
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ret->nr_objs = 0;
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ret->objs = NULL;
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ret->ctor = ctor;
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return ret;
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}
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