48     * - a pointer to the child pool to which this element belongs, or
62       /* Next page in the same child pool. */
83  * pool has been destroyed). Mark the element as freed and free the whole page
99  * Create a parent pool for the allocation of same-sized objects.
123  * Create a child pool linked to the given parent.
125 void slab_create_child(struct slab_child_pool *pool,  in slab_create_child()  argument
128    pool->parent = parent;  in slab_create_child()
129    pool->pages = NULL;  in slab_create_child()
130    pool->free = NULL;  in slab_create_child()
131    pool->migrated = NULL;  in slab_create_child()
135  * Destroy the child pool.
137  * Pages associated to the pool will be orphaned. They are eventually freed
140 void slab_destroy_child(struct slab_child_pool *pool)  in slab_destroy_child()  argument
142    if (!pool->parent)  in slab_destroy_child()
145    simple_mtx_lock(&pool->parent->mutex);  in slab_destroy_child()
147    while (pool->pages) {  in slab_destroy_child()
148       struct slab_page_header *page = pool->pages;  in slab_destroy_child()
149       pool->pages = page->u.next;  in slab_destroy_child()
150       p_atomic_set(&page->u.num_remaining, pool->parent->num_elements);  in slab_destroy_child()
152       for (unsigned i = 0; i < pool->parent->num_elements; ++i) {  in slab_destroy_child()
153          struct slab_element_header *elt = slab_get_element(pool->parent, page, i);  in slab_destroy_child()
158    while (pool->migrated) {  in slab_destroy_child()
159       struct slab_element_header *elt = pool->migrated;  in slab_destroy_child()
160       pool->migrated = elt->next;  in slab_destroy_child()
164    simple_mtx_unlock(&pool->parent->mutex);  in slab_destroy_child()
166    while (pool->free) {  in slab_destroy_child()
167       struct slab_element_header *elt = pool->free;  in slab_destroy_child()
168       pool->free = elt->next;  in slab_destroy_child()
173    pool->parent = NULL;  in slab_destroy_child()
177 slab_add_new_page(struct slab_child_pool *pool)  in slab_add_new_page()  argument
180       pool->parent->num_elements * pool->parent->element_size);  in slab_add_new_page()
185    for (unsigned i = 0; i < pool->parent->num_elements; ++i) {  in slab_add_new_page()
186       struct slab_element_header *elt = slab_get_element(pool->parent, page, i);  in slab_add_new_page()
187       elt->owner = (intptr_t)pool;  in slab_add_new_page()
190       elt->next = pool->free;  in slab_add_new_page()
191       pool->free = elt;  in slab_add_new_page()
195    page->u.next = pool->pages;  in slab_add_new_page()
196    pool->pages = page;  in slab_add_new_page()
202  * Allocate an object from the child pool. Single-threaded (i.e. the caller
203  * must ensure that no operation happens on the same child pool in another
207 slab_alloc(struct slab_child_pool *pool)  in slab_alloc()  argument
211    if (!pool->free) {  in slab_alloc()
213        * different child pool.  in slab_alloc()
215       simple_mtx_lock(&pool->parent->mutex);  in slab_alloc()
216       pool->free = pool->migrated;  in slab_alloc()
217       pool->migrated = NULL;  in slab_alloc()
218       simple_mtx_unlock(&pool->parent->mutex);  in slab_alloc()
221       if (!pool->free && !slab_add_new_page(pool))  in slab_alloc()
225    elt = pool->free;  in slab_alloc()
226    pool->free = elt->next;  in slab_alloc()
238 slab_zalloc(struct slab_child_pool *pool)  in slab_zalloc()  argument
240    void *r = slab_alloc(pool);  in slab_zalloc()
242       memset(r, 0, pool->parent->item_size);  in slab_zalloc()
248  * must ensure that no operation happens on the same child pool in another
251  * Freeing an object in a different child pool from the one where it was
252  * allocated is allowed, as long the pool belong to the same parent. No
255 void slab_free(struct slab_child_pool *pool, void *ptr)  in slab_free()  argument
263    if (p_atomic_read(&elt->owner) == (intptr_t)pool) {  in slab_free()
267       elt->next = pool->free;  in slab_free()
268       pool->free = elt;  in slab_free()
273    if (pool->parent)  in slab_free()
274       simple_mtx_lock(&pool->parent->mutex);  in slab_free()
276    /* Note: we _must_ re-read elt->owner here because the owning child pool  in slab_free()
285       if (pool->parent)  in slab_free()
286          simple_mtx_unlock(&pool->parent->mutex);  in slab_free()
288       if (pool->parent)  in slab_free()
289          simple_mtx_unlock(&pool->parent->mutex);  in slab_free()