[dpdk-dev] [PATCH v1 2/4] vhost: dynamically alloc async memory

[Patrick Fu]

alloc async internal memory buffer by rte_malloc(), replacing array
declaration inside vq structure. Dynamic allocation can help to save
memory footprint when async path is not registered.

Signed-off-by: Patrick Fu <patrick...@intel.com>
---
 lib/librte_vhost/vhost.c | 49 ++++++++++++++++++++++++----------------
 lib/librte_vhost/vhost.h |  4 ++--
 2 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index eca507836..ba374da67 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -324,6 +324,24 @@ cleanup_device(struct virtio_net *dev, int destroy)
        }
 }
 
+static void
+vhost_free_async_mem(struct vhost_virtqueue *vq)
+{
+       if (vq->async_pkts_pending)
+               rte_free(vq->async_pkts_pending);
+       if (vq->async_pkts_info)
+               rte_free(vq->async_pkts_info);
+       if (vq->it_pool)
+               rte_free(vq->it_pool);
+       if (vq->vec_pool)
+               rte_free(vq->vec_pool);
+
+       vq->async_pkts_pending = NULL;
+       vq->async_pkts_info = NULL;
+       vq->it_pool = NULL;
+       vq->vec_pool = NULL;
+}
+
 void
 free_vq(struct virtio_net *dev, struct vhost_virtqueue *vq)
 {
@@ -331,10 +349,7 @@ free_vq(struct virtio_net *dev, struct vhost_virtqueue *vq)
                rte_free(vq->shadow_used_packed);
        else {
                rte_free(vq->shadow_used_split);
-               if (vq->async_pkts_pending)
-                       rte_free(vq->async_pkts_pending);
-               if (vq->async_pkts_info)
-                       rte_free(vq->async_pkts_info);
+               vhost_free_async_mem(vq);
        }
        rte_free(vq->batch_copy_elems);
        rte_mempool_free(vq->iotlb_pool);
@@ -1576,13 +1591,15 @@ int rte_vhost_async_channel_register(int vid, uint16_t 
queue_id,
        vq->async_pkts_info = rte_malloc(NULL,
                        vq->size * sizeof(struct async_inflight_info),
                        RTE_CACHE_LINE_SIZE);
-       if (!vq->async_pkts_pending || !vq->async_pkts_info) {
-               if (vq->async_pkts_pending)
-                       rte_free(vq->async_pkts_pending);
-
-               if (vq->async_pkts_info)
-                       rte_free(vq->async_pkts_info);
-
+       vq->it_pool = rte_malloc(NULL,
+                       VHOST_MAX_ASYNC_IT * sizeof(struct rte_vhost_iov_iter),
+                       RTE_CACHE_LINE_SIZE);
+       vq->vec_pool = rte_malloc(NULL,
+                       VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
+                       RTE_CACHE_LINE_SIZE);
+       if (!vq->async_pkts_pending || !vq->async_pkts_info ||
+               !vq->it_pool || !vq->vec_pool) {
+               vhost_free_async_mem(vq);
                VHOST_LOG_CONFIG(ERR,
                                "async register failed: cannot allocate memory 
for vq data "
                                "(vid %d, qid: %d)\n", vid, queue_id);
@@ -1630,15 +1647,7 @@ int rte_vhost_async_channel_unregister(int vid, uint16_t 
queue_id)
                goto out;
        }
 
-       if (vq->async_pkts_pending) {
-               rte_free(vq->async_pkts_pending);
-               vq->async_pkts_pending = NULL;
-       }
-
-       if (vq->async_pkts_info) {
-               rte_free(vq->async_pkts_info);
-               vq->async_pkts_info = NULL;
-       }
+       vhost_free_async_mem(vq);
 
        vq->async_ops.transfer_data = NULL;
        vq->async_ops.check_completed_copies = NULL;
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 28aa77380..0af0ac23d 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -218,8 +218,8 @@ struct vhost_virtqueue {
        /* operation callbacks for async dma */
        struct rte_vhost_async_channel_ops      async_ops;
 
-       struct rte_vhost_iov_iter it_pool[VHOST_MAX_ASYNC_IT];
-       struct iovec vec_pool[VHOST_MAX_ASYNC_VEC];
+       struct rte_vhost_iov_iter *it_pool;
+       struct iovec *vec_pool;
 
        /* async data transfer status */
        uintptr_t       **async_pkts_pending;
-- 
2.18.4