gpudev: remove unnecessary memory barrier

Remove unnecessary rte_gpu_wmb from rte_gpu_comm_populate_list_pkts.
It causes a performance degradation in case of NVIDIA GPU V100.

This change doesn't affect any functionality as the status resides
in CPU registered memory.

Fixes: c7ebd65c1372 ("gpudev: add communication list")

Signed-off-by: Elena Agostini <eagostini@nvidia.com>

diff --git a/lib/gpudev/gpudev.c b/lib/gpudev/gpudev.c
index 1d8200e..9ae36db 100644 (file)
--- a/lib/gpudev/gpudev.c
+++ b/lib/gpudev/gpudev.c
@@ -877,7 +877,6 @@ rte_gpu_comm_populate_list_pkts(struct rte_gpu_comm_list *comm_list_item,
        RTE_GPU_VOLATILE(comm_list_item->num_pkts) = num_mbufs;
        rte_gpu_wmb(comm_list_item->dev_id);
        RTE_GPU_VOLATILE(comm_list_item->status) = RTE_GPU_COMM_LIST_READY;
-       rte_gpu_wmb(comm_list_item->dev_id);
 
        return 0;
 }