Function find_biggest_element

dpdk/lib/eal/common/malloc_heap.c:183–223

* Iterates through the freelist for a heap to find a free element with the * biggest size and requested alignment. Will also set size to whatever element * size that was found. * Returns null on failure, or pointer to element on success. */

 * Returns null on failure, or pointer to element on success.
 */
static struct malloc_elem *
find_biggest_element(struct malloc_heap *heap, size_t *size,
		unsigned int flags, size_t align, bool contig)
{
	struct malloc_elem *elem, *max_elem = NULL;
	size_t idx, max_size = 0;

	for (idx = 0; idx < RTE_HEAP_NUM_FREELISTS; idx++) {
		for (elem = LIST_FIRST(&heap->free_head[idx]);
				!!elem; elem = LIST_NEXT(elem, free_list)) {
			size_t cur_size;
			if ((flags & RTE_MEMZONE_SIZE_HINT_ONLY) == 0 &&
					!check_hugepage_sz(flags,
						elem->msl->page_sz))
				continue;
			if (contig) {
				cur_size =
					malloc_elem_find_max_iova_contig(elem,
							align);
			} else {
				void *data_start = RTE_PTR_ADD(elem,
						MALLOC_ELEM_HEADER_LEN);
				void *data_end = RTE_PTR_ADD(elem, elem->size -
						MALLOC_ELEM_TRAILER_LEN);
				void *aligned = RTE_PTR_ALIGN_CEIL(data_start,
						align);
				/* check if aligned data start is beyond end */
				if (aligned >= data_end)
					continue;
				cur_size = RTE_PTR_DIFF(data_end, aligned);
			}
			if (cur_size > max_size) {
				max_size = cur_size;
				max_elem = elem;
			}
		}
	}

	*size = max_size;
	return max_elem;
}

/*
 * Main function to allocate a block of memory from the heap.