[v2,2/2] vdpa/mlx5: retry VAR allocation during vDPA restart
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Commit Message
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@dpdk.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Reviewed-by: Matan Azrad <matan@nvidia.com>
---
drivers/vdpa/mlx5/mlx5_vdpa.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
Comments
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@dpdk.org
>
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> Reviewed-by: Matan Azrad <matan@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@redhat.com>
Thanks,
Maxime
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@dpdk.org
>
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> Reviewed-by: Matan Azrad <matan@nvidia.com>
> ---
> drivers/vdpa/mlx5/mlx5_vdpa.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
Applied to dpdk-next-virtio/main.
Thanks,
Maxime
@@ -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;