[dpdk-dev] [PATCH v2 2/2] vdpa/mlx5: retry VAR allocation during vDPA restart
Maxime Coquelin
maxime.coquelin at redhat.com
Thu Oct 21 11:40:21 CEST 2021
On 10/15/21 17:05, Xueming Li wrote:
> VAR is the device memory space for the virtio queues doorbells, qemu
> could mmap it to directly to speed up doorbell push.
>
> On a busy system, Qemu takes time to release VAR resources during driver
> shutdown. If vdpa restarted quickly, the VAR allocation failed with
> error 28 since the VAR is singleton resource per device.
>
> This patch adds retry mechanism for VAR allocation.
>
> Fixes: 4cae722c1b06 ("vdpa/mlx5: move virtual doorbell alloc to probe")
> Cc: stable at dpdk.org
>
> Signed-off-by: Xueming Li <xuemingl at nvidia.com>
> Reviewed-by: Matan Azrad <matan at nvidia.com>
> ---
> drivers/vdpa/mlx5/mlx5_vdpa.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
> index 6d17d7a6f3e..991739e9840 100644
> --- a/drivers/vdpa/mlx5/mlx5_vdpa.c
> +++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
> @@ -693,7 +693,14 @@ mlx5_vdpa_dev_probe(struct rte_device *dev)
> if (attr.num_lag_ports == 0)
> priv->num_lag_ports = 1;
> priv->ctx = ctx;
> - priv->var = mlx5_glue->dv_alloc_var(ctx, 0);
> + for (retry = 0; retry < 7; retry++) {
> + priv->var = mlx5_glue->dv_alloc_var(ctx, 0);
> + if (priv->var != NULL)
> + break;
> + DRV_LOG(WARNING, "Failed to allocate VAR, retry %d.\n", retry);
> + /* Wait Qemu release VAR during vdpa restart, 0.1 sec based. */
> + usleep(100000U << retry);
> + }
> if (!priv->var) {
> DRV_LOG(ERR, "Failed to allocate VAR %u.", errno);
> goto error;
>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Thanks,
Maxime
More information about the dev
mailing list