elem->heap = heap;
elem->ms = ms;
elem->prev = NULL;
+ elem->next = NULL;
memset(&elem->free_list, 0, sizeof(elem->free_list));
elem->state = ELEM_FREE;
elem->size = size;
set_trailer(elem);
}
-/*
- * Initialize a dummy malloc_elem header for the end-of-memseg marker
- */
void
-malloc_elem_mkend(struct malloc_elem *elem, struct malloc_elem *prev)
+malloc_elem_insert(struct malloc_elem *elem)
{
- malloc_elem_init(elem, prev->heap, prev->ms, 0);
- elem->prev = prev;
- elem->state = ELEM_BUSY; /* mark busy so its never merged */
+ struct malloc_elem *prev_elem, *next_elem;
+ struct malloc_heap *heap = elem->heap;
+
+ if (heap->first == NULL && heap->last == NULL) {
+ /* if empty heap */
+ heap->first = elem;
+ heap->last = elem;
+ prev_elem = NULL;
+ next_elem = NULL;
+ } else if (elem < heap->first) {
+ /* if lower than start */
+ prev_elem = NULL;
+ next_elem = heap->first;
+ heap->first = elem;
+ } else if (elem > heap->last) {
+ /* if higher than end */
+ prev_elem = heap->last;
+ next_elem = NULL;
+ heap->last = elem;
+ } else {
+ /* the new memory is somewhere inbetween start and end */
+ uint64_t dist_from_start, dist_from_end;
+
+ dist_from_end = RTE_PTR_DIFF(heap->last, elem);
+ dist_from_start = RTE_PTR_DIFF(elem, heap->first);
+
+ /* check which is closer, and find closest list entries */
+ if (dist_from_start < dist_from_end) {
+ prev_elem = heap->first;
+ while (prev_elem->next < elem)
+ prev_elem = prev_elem->next;
+ next_elem = prev_elem->next;
+ } else {
+ next_elem = heap->last;
+ while (next_elem->prev > elem)
+ next_elem = next_elem->prev;
+ prev_elem = next_elem->prev;
+ }
+ }
+
+ /* insert new element */
+ elem->prev = prev_elem;
+ elem->next = next_elem;
+ if (prev_elem)
+ prev_elem->next = elem;
+ if (next_elem)
+ next_elem->prev = elem;
}
/*
static void
split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
{
- struct malloc_elem *next_elem = RTE_PTR_ADD(elem, elem->size);
+ struct malloc_elem *next_elem = elem->next;
const size_t old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
const size_t new_elem_size = elem->size - old_elem_size;
malloc_elem_init(split_pt, elem->heap, elem->ms, new_elem_size);
split_pt->prev = elem;
- next_elem->prev = split_pt;
+ split_pt->next = next_elem;
+ if (next_elem)
+ next_elem->prev = split_pt;
+ else
+ elem->heap->last = split_pt;
+ elem->next = split_pt;
elem->size = old_elem_size;
set_trailer(elem);
}
+/*
+ * our malloc heap is a doubly linked list, so doubly remove our element.
+ */
+static void __rte_unused
+remove_elem(struct malloc_elem *elem)
+{
+ struct malloc_elem *next, *prev;
+ next = elem->next;
+ prev = elem->prev;
+
+ if (next)
+ next->prev = prev;
+ else
+ elem->heap->last = prev;
+ if (prev)
+ prev->next = next;
+ else
+ elem->heap->first = next;
+
+ elem->prev = NULL;
+ elem->next = NULL;
+}
+
+static int
+next_elem_is_adjacent(struct malloc_elem *elem)
+{
+ return elem->next == RTE_PTR_ADD(elem, elem->size);
+}
+
+static int
+prev_elem_is_adjacent(struct malloc_elem *elem)
+{
+ return elem == RTE_PTR_ADD(elem->prev, elem->prev->size);
+}
+
/*
* Given an element size, compute its freelist index.
* We free an element into the freelist containing similarly-sized elements.
split_elem(elem, new_free_elem);
malloc_elem_free_list_insert(new_free_elem);
+
+ if (elem == elem->heap->last)
+ elem->heap->last = new_free_elem;
}
if (old_elem_size < MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
static inline void
join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
{
- struct malloc_elem *next = RTE_PTR_ADD(elem2, elem2->size);
+ struct malloc_elem *next = elem2->next;
elem1->size += elem2->size;
- next->prev = elem1;
+ if (next)
+ next->prev = elem1;
+ else
+ elem1->heap->last = elem1;
+ elem1->next = next;
+}
+
+static struct malloc_elem *
+elem_join_adjacent_free(struct malloc_elem *elem)
+{
+ /*
+ * check if next element exists, is adjacent and is free, if so join
+ * with it, need to remove from free list.
+ */
+ if (elem->next != NULL && elem->next->state == ELEM_FREE &&
+ next_elem_is_adjacent(elem)) {
+ void *erase;
+
+ /* we will want to erase the trailer and header */
+ erase = RTE_PTR_SUB(elem->next, MALLOC_ELEM_TRAILER_LEN);
+
+ /* remove from free list, join to this one */
+ elem_free_list_remove(elem->next);
+ join_elem(elem, elem->next);
+
+ /* erase header and trailer */
+ memset(erase, 0, MALLOC_ELEM_OVERHEAD);
+ }
+
+ /*
+ * check if prev element exists, is adjacent and is free, if so join
+ * with it, need to remove from free list.
+ */
+ if (elem->prev != NULL && elem->prev->state == ELEM_FREE &&
+ prev_elem_is_adjacent(elem)) {
+ struct malloc_elem *new_elem;
+ void *erase;
+
+ /* we will want to erase trailer and header */
+ erase = RTE_PTR_SUB(elem, MALLOC_ELEM_TRAILER_LEN);
+
+ /* remove from free list, join to this one */
+ elem_free_list_remove(elem->prev);
+
+ new_elem = elem->prev;
+ join_elem(new_elem, elem);
+
+ /* erase header and trailer */
+ memset(erase, 0, MALLOC_ELEM_OVERHEAD);
+
+ elem = new_elem;
+ }
+
+ return elem;
}
/*
int
malloc_elem_free(struct malloc_elem *elem)
{
- size_t sz = elem->size - sizeof(*elem) - MALLOC_ELEM_TRAILER_LEN;
- uint8_t *ptr = (uint8_t *)&elem[1];
- struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
- if (next->state == ELEM_FREE){
- /* remove from free list, join to this one */
- elem_free_list_remove(next);
- join_elem(elem, next);
- sz += (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
- }
+ void *ptr;
+ size_t data_len;
+
+ ptr = RTE_PTR_ADD(elem, sizeof(*elem));
+ data_len = elem->size - MALLOC_ELEM_OVERHEAD;
+
+ elem = elem_join_adjacent_free(elem);
- /* check if previous element is free, if so join with it and return,
- * need to re-insert in free list, as that element's size is changing
- */
- if (elem->prev != NULL && elem->prev->state == ELEM_FREE) {
- elem_free_list_remove(elem->prev);
- join_elem(elem->prev, elem);
- sz += (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
- ptr -= (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
- elem = elem->prev;
- }
malloc_elem_free_list_insert(elem);
/* decrease heap's count of allocated elements */
elem->heap->alloc_count--;
- memset(ptr, 0, sz);
+ memset(ptr, 0, data_len);
return 0;
}
malloc_elem_resize(struct malloc_elem *elem, size_t size)
{
const size_t new_size = size + elem->pad + MALLOC_ELEM_OVERHEAD;
+
/* if we request a smaller size, then always return ok */
if (elem->size >= new_size)
return 0;
- struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
- if (next ->state != ELEM_FREE)
+ /* check if there is a next element, it's free and adjacent */
+ if (!elem->next || elem->next->state != ELEM_FREE ||
+ !next_elem_is_adjacent(elem))
return -1;
- if (elem->size + next->size < new_size)
+ if (elem->size + elem->next->size < new_size)
return -1;
/* we now know the element fits, so remove from free list,
* join the two
*/
- elem_free_list_remove(next);
- join_elem(elem, next);
+ elem_free_list_remove(elem->next);
+ join_elem(elem, elem->next);
if (elem->size - new_size >= MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD) {
/* now we have a big block together. Lets cut it down a bit, by splitting */
git.droids-corp.org / dpdk.git / commitdiff