On 10/28/19 5:01 PM, Olivier Matz wrote:
When populating a mempool, ensure that objects are not located across
several pages, except if user did not request iova contiguous objects.
I think it breaks distribution across memory channels which could
affect performance significantly.
Signed-off-by: Vamsi Krishna Attunuru <vattun...@marvell.com>
Signed-off-by: Olivier Matz <olivier.m...@6wind.com>
---
lib/librte_mempool/rte_mempool.c | 23 +++++-----------
lib/librte_mempool/rte_mempool_ops_default.c | 29 ++++++++++++++++++--
2 files changed, 33 insertions(+), 19 deletions(-)
diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 7664764e5..b23fd1b06 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -428,8 +428,6 @@ rte_mempool_get_page_size(struct rte_mempool *mp, size_t
*pg_sz)
if (!need_iova_contig_obj)
*pg_sz = 0;
- else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA)
- *pg_sz = 0;
else if (rte_eal_has_hugepages() || alloc_in_ext_mem)
*pg_sz = get_min_page_size(mp->socket_id);
else
@@ -478,17 +476,15 @@ rte_mempool_populate_default(struct rte_mempool *mp)
* then just set page shift and page size to 0, because the user has
* indicated that there's no need to care about anything.
*
- * if we do need contiguous objects, there is also an option to reserve
- * the entire mempool memory as one contiguous block of memory, in
- * which case the page shift and alignment wouldn't matter as well.
+ * if we do need contiguous objects (if a mempool driver has its
+ * own calc_size() method returning min_chunk_size = mem_size),
+ * there is also an option to reserve the entire mempool memory
+ * as one contiguous block of memory.
*
* if we require contiguous objects, but not necessarily the entire
- * mempool reserved space to be contiguous, then there are two options.
- *
- * if our IO addresses are virtual, not actual physical (IOVA as VA
- * case), then no page shift needed - our memory allocation will give us
- * contiguous IO memory as far as the hardware is concerned, so
- * act as if we're getting contiguous memory.
+ * mempool reserved space to be contiguous, pg_sz will be != 0,
+ * and the default ops->populate() will take care of not placing
+ * objects across pages.
*
* if our IO addresses are physical, we may get memory from bigger
* pages, or we might get memory from smaller pages, and how much of it
@@ -501,11 +497,6 @@ rte_mempool_populate_default(struct rte_mempool *mp)
*
* If we fail to get enough contiguous memory, then we'll go and
* reserve space in smaller chunks.
- *
- * We also have to take into account the fact that memory that we're
- * going to allocate from can belong to an externally allocated memory
- * area, in which case the assumption of IOVA as VA mode being
- * synonymous with IOVA contiguousness will not hold.
*/
need_iova_contig_obj = !(mp->flags & MEMPOOL_F_NO_IOVA_CONTIG);
diff --git a/lib/librte_mempool/rte_mempool_ops_default.c
b/lib/librte_mempool/rte_mempool_ops_default.c
index f6aea7662..dd09a0a32 100644
--- a/lib/librte_mempool/rte_mempool_ops_default.c
+++ b/lib/librte_mempool/rte_mempool_ops_default.c
@@ -61,21 +61,44 @@ rte_mempool_op_calc_mem_size_default(const struct
rte_mempool *mp,
return mem_size;
}
+/* Returns -1 if object crosses a page boundary, else returns 0 */
+static int
+check_obj_bounds(char *obj, size_t pg_sz, size_t elt_sz)
+{
+ if (pg_sz == 0)
+ return 0;
+ if (elt_sz > pg_sz)
+ return 0;
+ if (RTE_PTR_ALIGN(obj, pg_sz) != RTE_PTR_ALIGN(obj + elt_sz - 1, pg_sz))
+ return -1;
+ return 0;
+}
+
int
rte_mempool_op_populate_default(struct rte_mempool *mp, unsigned int max_objs,
void *vaddr, rte_iova_t iova, size_t len,
rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg)
{
- size_t total_elt_sz;
+ char *va = vaddr;
+ size_t total_elt_sz, pg_sz;
size_t off;
unsigned int i;
void *obj;
+ rte_mempool_get_page_size(mp, &pg_sz);
+
The function may return an error which should be taken into account here.
total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
- for (off = 0, i = 0; off + total_elt_sz <= len && i < max_objs; i++) {
+ for (off = 0, i = 0; i < max_objs; i++) {
+ /* align offset to next page start if required */
+ if (check_obj_bounds(va + off, pg_sz, total_elt_sz) < 0)
+ off += RTE_PTR_ALIGN_CEIL(va + off, pg_sz) - (va + off);
+
+ if (off + total_elt_sz > len)
+ break;
+
off += mp->header_size;
- obj = (char *)vaddr + off;
+ obj = va + off;
obj_cb(mp, obj_cb_arg, obj,
(iova == RTE_BAD_IOVA) ? RTE_BAD_IOVA : (iova + off));
rte_mempool_ops_enqueue_bulk(mp, &obj, 1);
