mempool: clarify default populate function

No functional change.
Clarify the populate function to make future changes easier to
understand.

Rename the variables:
- to avoid negation in the name
- to have more understandable names

Remove useless variable (no_pageshift is equivalent to pg_sz == 0).

Remove duplicate affectation of "external" variable.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 7260ce0..0f29e87 100644 (file)
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -429,24 +429,18 @@ rte_mempool_populate_default(struct rte_mempool *mp)
        rte_iova_t iova;
        unsigned mz_id, n;
        int ret;
-       bool no_contig, try_contig, no_pageshift, external;
+       bool need_iova_contig_obj;
+       bool try_iova_contig_mempool;
+       bool alloc_in_ext_mem;
 
        ret = mempool_ops_alloc_once(mp);
        if (ret != 0)
                return ret;
 
-       /* check if we can retrieve a valid socket ID */
-       ret = rte_malloc_heap_socket_is_external(mp->socket_id);
-       if (ret < 0)
-               return -EINVAL;
-       external = ret;
-
        /* mempool must not be populated */
        if (mp->nb_mem_chunks != 0)
                return -EEXIST;
 
-       no_contig = mp->flags & MEMPOOL_F_NO_IOVA_CONTIG;
-
        /*
         * the following section calculates page shift and page size values.
         *
@@ -496,16 +490,23 @@ rte_mempool_populate_default(struct rte_mempool *mp)
         * to go for contiguous memory even if we're in no-huge mode, because
         * external memory may in fact be IOVA-contiguous.
         */
-       external = rte_malloc_heap_socket_is_external(mp->socket_id) == 1;
-       no_pageshift = no_contig ||
-                       (!external && rte_eal_iova_mode() == RTE_IOVA_VA);
-       try_contig = !no_contig && !no_pageshift &&
-                       (rte_eal_has_hugepages() || external);
 
-       if (no_pageshift) {
+       /* check if we can retrieve a valid socket ID */
+       ret = rte_malloc_heap_socket_is_external(mp->socket_id);
+       if (ret < 0)
+               return -EINVAL;
+       alloc_in_ext_mem = (ret == 1);
+       need_iova_contig_obj = !(mp->flags & MEMPOOL_F_NO_IOVA_CONTIG);
+       try_iova_contig_mempool = false;
+
+       if (!need_iova_contig_obj) {
+               pg_sz = 0;
+               pg_shift = 0;
+       } else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA) {
                pg_sz = 0;
                pg_shift = 0;
-       } else if (try_contig) {
+       } else if (rte_eal_has_hugepages() || alloc_in_ext_mem) {
+               try_iova_contig_mempool = true;
                pg_sz = get_min_page_size(mp->socket_id);
                pg_shift = rte_bsf32(pg_sz);
        } else {
@@ -517,7 +518,7 @@ rte_mempool_populate_default(struct rte_mempool *mp)
                size_t min_chunk_size;
                unsigned int flags;
 
-               if (try_contig || no_pageshift)
+               if (try_iova_contig_mempool || pg_sz == 0)
                        mem_size = rte_mempool_ops_calc_mem_size(mp, n,
                                        0, &min_chunk_size, &align);
                else
@@ -541,7 +542,7 @@ rte_mempool_populate_default(struct rte_mempool *mp)
                /* if we're trying to reserve contiguous memory, add appropriate
                 * memzone flag.
                 */
-               if (try_contig)
+               if (try_iova_contig_mempool)
                        flags |= RTE_MEMZONE_IOVA_CONTIG;
 
                mz = rte_memzone_reserve_aligned(mz_name, mem_size,
@@ -551,8 +552,9 @@ rte_mempool_populate_default(struct rte_mempool *mp)
                 * minimum required contiguous chunk fits minimum page, adjust
                 * memzone size to the page size, and try again.
                 */
-               if (mz == NULL && try_contig && min_chunk_size <= pg_sz) {
-                       try_contig = false;
+               if (mz == NULL && try_iova_contig_mempool &&
+                               min_chunk_size <= pg_sz) {
+                       try_iova_contig_mempool = false;
                        flags &= ~RTE_MEMZONE_IOVA_CONTIG;
 
                        mem_size = rte_mempool_ops_calc_mem_size(mp, n,
@@ -587,12 +589,12 @@ rte_mempool_populate_default(struct rte_mempool *mp)
                        goto fail;
                }
 
-               if (no_contig)
-                       iova = RTE_BAD_IOVA;
-               else
+               if (need_iova_contig_obj)
                        iova = mz->iova;
+               else
+                       iova = RTE_BAD_IOVA;
 
-               if (no_pageshift || try_contig)
+               if (try_iova_contig_mempool || pg_sz == 0)
                        ret = rte_mempool_populate_iova(mp, mz->addr,
                                iova, mz->len,
                                rte_mempool_memchunk_mz_free,