From 6956a48cabbb5c98098aaf0116c255209b8f4e87 Mon Sep 17 00:00:00 2001
From: Xueming Li <xuemingl@nvidia.com>
Date: Wed, 2 Dec 2020 23:36:40 +0000
Subject: [PATCH] vdpa/mlx5: set polling mode default delay to zero
To improve throughput and latency, this patch allows Rx polling timer
delay to 0us.
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
doc/guides/vdpadevs/mlx5.rst | 3 +--
drivers/vdpa/mlx5/mlx5_vdpa.c | 9 +++------
2 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/doc/guides/vdpadevs/mlx5.rst b/doc/guides/vdpadevs/mlx5.rst
index 3a6d88362d..903fdb0e60 100644
--- a/doc/guides/vdpadevs/mlx5.rst
+++ b/doc/guides/vdpadevs/mlx5.rst
@@ -125,8 +125,7 @@ Driver options
- 0, A nonzero value to set timer step in micro-seconds. The timer thread
dynamic delay change steps according to this value. Default value is 1us.
- - 1, A nonzero value to set fixed timer delay in micro-seconds. Default value
- is 100us.
+ - 1, A value to set fixed timer delay in micro-seconds. Default value is 0us.
- ``no_traffic_time`` parameter [int]
diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
index b64f364eb7..5020a99fae 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -651,12 +651,9 @@ mlx5_vdpa_config_get(struct rte_devargs *devargs, struct mlx5_vdpa_priv *priv)
return;
rte_kvargs_process(kvlist, NULL, mlx5_vdpa_args_check_handler, priv);
rte_kvargs_free(kvlist);
- if (!priv->event_us) {
- if (priv->event_mode == MLX5_VDPA_EVENT_MODE_DYNAMIC_TIMER)
- priv->event_us = MLX5_VDPA_DEFAULT_TIMER_STEP_US;
- else if (priv->event_mode == MLX5_VDPA_EVENT_MODE_FIXED_TIMER)
- priv->event_us = MLX5_VDPA_DEFAULT_TIMER_DELAY_US;
- }
+ if (!priv->event_us &&
+ priv->event_mode == MLX5_VDPA_EVENT_MODE_DYNAMIC_TIMER)
+ priv->event_us = MLX5_VDPA_DEFAULT_TIMER_STEP_US;
DRV_LOG(DEBUG, "event mode is %d.", priv->event_mode);
DRV_LOG(DEBUG, "event_us is %u us.", priv->event_us);
DRV_LOG(DEBUG, "no traffic time is %u s.", priv->no_traffic_time_s);
--
2.39.5