Function alloc_seg_walk

dpdk/lib/eal/linux/eal_memalloc.c:813–942

	bool exact;
};
static int
alloc_seg_walk(const struct rte_memseg_list *msl, void *arg)
{
	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
	struct alloc_walk_param *wa = arg;
	struct rte_memseg_list *cur_msl;
	size_t page_sz;
	int cur_idx, start_idx, j, dir_fd = -1;
	unsigned int msl_idx, need, i;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();

	if (msl->page_sz != wa->page_sz)
		return 0;
	if (msl->socket_id != wa->socket)
		return 0;

	page_sz = (size_t)msl->page_sz;

	msl_idx = msl - mcfg->memsegs;
	cur_msl = &mcfg->memsegs[msl_idx];

	need = wa->n_segs;

	/* try finding space in memseg list */
	if (wa->exact) {
		/* if we require exact number of pages in a list, find them */
		cur_idx = rte_fbarray_find_next_n_free(&cur_msl->memseg_arr, 0,
				need);
		if (cur_idx < 0)
			return 0;
		start_idx = cur_idx;
	} else {
		int cur_len;

		/* we don't require exact number of pages, so we're going to go
		 * for best-effort allocation. that means finding the biggest
		 * unused block, and going with that.
		 */
		cur_idx = rte_fbarray_find_biggest_free(&cur_msl->memseg_arr,
				0);
		if (cur_idx < 0)
			return 0;
		start_idx = cur_idx;
		/* adjust the size to possibly be smaller than original
		 * request, but do not allow it to be bigger.
		 */
		cur_len = rte_fbarray_find_contig_free(&cur_msl->memseg_arr,
				cur_idx);
		need = RTE_MIN(need, (unsigned int)cur_len);
	}

	/* do not allow any page allocations during the time we're allocating,
	 * because file creation and locking operations are not atomic,
	 * and we might be the first or the last ones to use a particular page,
	 * so we need to ensure atomicity of every operation.
	 *
	 * during init, we already hold a write lock, so don't try to take out