From: Claudiu Manoil <claudiu.manoil@nxp.com>
Date: Tue, 21 Jul 2020 10:55:17 +0300
Subject: enetc: Refine buffer descriptor ring sizes
Git-commit: 02293dd4b79ec16ae0f680222768fb1582f03b42
Patch-mainline: v5.9-rc1
References: jsc#SLE-12251
It's time to differentiate between Rx and Tx ring sizes.
Not only Tx rings are processed differently than Rx rings,
but their default number also differs - i.e. up to 8 Tx rings
per device (8 traffic classes) vs. 2 Rx rings (one per CPU).
So let's set Tx rings sizes to half the size of the Rx rings
for now, to be conservative.
The default ring sizes were decreased as well (to the next
lower power of 2), to reduce the memory footprint, buffering
etc., since the measurements I've made so far show that the
rings are very unlikely to get full.
This change also anticipates the introduction of the
dynamic interrupt moderation (dim) algorithm which operates
on maximum packet thresholds of 256 packets for Rx and 128
packets for Tx.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
drivers/net/ethernet/freescale/enetc/enetc.c | 4 ++--
drivers/net/ethernet/freescale/enetc/enetc.h | 5 +++--
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 3f32b85ba2cf..d91e52618681 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1064,8 +1064,8 @@ void enetc_init_si_rings_params(struct enetc_ndev_priv *priv)
struct enetc_si *si = priv->si;
int cpus = num_online_cpus();
- priv->tx_bd_count = ENETC_BDR_DEFAULT_SIZE;
- priv->rx_bd_count = ENETC_BDR_DEFAULT_SIZE;
+ priv->tx_bd_count = ENETC_TX_RING_DEFAULT_SIZE;
+ priv->rx_bd_count = ENETC_RX_RING_DEFAULT_SIZE;
/* Enable all available TX rings in order to configure as many
* priorities as possible, when needed.
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index b705464f6882..0dd8ee179753 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -44,8 +44,9 @@ struct enetc_ring_stats {
unsigned int rx_alloc_errs;
};
-#define ENETC_BDR_DEFAULT_SIZE 1024
-#define ENETC_DEFAULT_TX_WORK 256
+#define ENETC_RX_RING_DEFAULT_SIZE 512
+#define ENETC_TX_RING_DEFAULT_SIZE 256
+#define ENETC_DEFAULT_TX_WORK (ENETC_TX_RING_DEFAULT_SIZE / 2)
struct enetc_bdr {
struct device *dev; /* for DMA mapping */
--
2.26.2