ixgbe: Make better use of memory allocations in one-buffer mode w/ RSC
This patch improves the memory utilization with RSC when in one-buffer
mode. This is accomplished by making the default buffer sizes match up
with the standard memory allocation sizes minus 1K for shared info and
padding overhead. By doing this CPU utilization when doing large receives
can be reduced by as much as 8%.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index 209286c..2c9fdf8 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -72,10 +72,13 @@
/* Supported Rx Buffer Sizes */
#define IXGBE_RXBUFFER_512 512 /* Used for packet split */
-#define IXGBE_RXBUFFER_2048 2048
-#define IXGBE_RXBUFFER_4096 4096
-#define IXGBE_RXBUFFER_8192 8192
-#define IXGBE_MAX_RXBUFFER 16384 /* largest size for a single descriptor */
+#define IXGBE_RXBUFFER_2K 2048
+#define IXGBE_RXBUFFER_3K 3072
+#define IXGBE_RXBUFFER_4K 4096
+#define IXGBE_RXBUFFER_7K 7168
+#define IXGBE_RXBUFFER_8K 8192
+#define IXGBE_RXBUFFER_15K 15360
+#define IXGBE_MAX_RXBUFFER 16384 /* largest size for a single descriptor */
/*
* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN mans we
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index b8410bc..46f4ecf1 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -1539,7 +1539,7 @@
rx_ring->dev = &adapter->pdev->dev;
rx_ring->netdev = adapter->netdev;
rx_ring->reg_idx = adapter->rx_ring[0]->reg_idx;
- rx_ring->rx_buf_len = IXGBE_RXBUFFER_2048;
+ rx_ring->rx_buf_len = IXGBE_RXBUFFER_2K;
rx_ring->numa_node = adapter->node;
err = ixgbe_setup_rx_resources(rx_ring);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index ce59dc6..a4103ef 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -499,7 +499,7 @@
rx_ring->rx_buf_len, true);
if (rx_ring->rx_buf_len
- < IXGBE_RXBUFFER_2048)
+ < IXGBE_RXBUFFER_2K)
print_hex_dump(KERN_INFO, "",
DUMP_PREFIX_ADDRESS, 16, 1,
phys_to_virt(
@@ -2644,9 +2644,9 @@
rscctrl |= IXGBE_RSCCTL_MAXDESC_1;
#endif
} else {
- if (rx_buf_len < IXGBE_RXBUFFER_4096)
+ if (rx_buf_len < IXGBE_RXBUFFER_4K)
rscctrl |= IXGBE_RSCCTL_MAXDESC_16;
- else if (rx_buf_len < IXGBE_RXBUFFER_8192)
+ else if (rx_buf_len < IXGBE_RXBUFFER_8K)
rscctrl |= IXGBE_RSCCTL_MAXDESC_8;
else
rscctrl |= IXGBE_RSCCTL_MAXDESC_4;
@@ -2879,17 +2879,6 @@
if (hw->mac.type == ixgbe_mac_82599EB)
adapter->flags &= ~IXGBE_FLAG_RX_PS_ENABLED;
- /* Set the RX buffer length according to the mode */
- if (adapter->flags & IXGBE_FLAG_RX_PS_ENABLED) {
- rx_buf_len = IXGBE_RX_HDR_SIZE;
- } else {
- if (!(adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) &&
- (netdev->mtu <= ETH_DATA_LEN))
- rx_buf_len = MAXIMUM_ETHERNET_VLAN_SIZE;
- else
- rx_buf_len = ALIGN(max_frame + VLAN_HLEN, 1024);
- }
-
#ifdef IXGBE_FCOE
/* adjust max frame to be able to do baby jumbo for FCoE */
if ((adapter->flags & IXGBE_FLAG_FCOE_ENABLED) &&
@@ -2905,6 +2894,30 @@
IXGBE_WRITE_REG(hw, IXGBE_MHADD, mhadd);
}
+ /* MHADD will allow an extra 4 bytes past for vlan tagged frames */
+ max_frame += VLAN_HLEN;
+
+ /* Set the RX buffer length according to the mode */
+ if (adapter->flags & IXGBE_FLAG_RX_PS_ENABLED) {
+ rx_buf_len = IXGBE_RX_HDR_SIZE;
+ } else {
+ if (!(adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) &&
+ (netdev->mtu <= ETH_DATA_LEN))
+ rx_buf_len = MAXIMUM_ETHERNET_VLAN_SIZE;
+ /*
+ * Make best use of allocation by using all but 1K of a
+ * power of 2 allocation that will be used for skb->head.
+ */
+ else if (max_frame <= IXGBE_RXBUFFER_3K)
+ rx_buf_len = IXGBE_RXBUFFER_3K;
+ else if (max_frame <= IXGBE_RXBUFFER_7K)
+ rx_buf_len = IXGBE_RXBUFFER_7K;
+ else if (max_frame <= IXGBE_RXBUFFER_15K)
+ rx_buf_len = IXGBE_RXBUFFER_15K;
+ else
+ rx_buf_len = IXGBE_MAX_RXBUFFER;
+ }
+
hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
/* set jumbo enable since MHADD.MFS is keeping size locked at max_frame */
hlreg0 |= IXGBE_HLREG0_JUMBOEN;