This patch sets PCIe relax ordering for SPARC arch by setting dma attr
DMA_ATTR_WEAK_ORDERING for every tx and rx DMA map/unmap.
This has shown 10x increase in performance numbers.
e.g.
iperf TCP test with 10 threads on SPARC S7
Test 1: Without this patch
[root@brm-snt1-03 net]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[ 4] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40926 [ 5] local
16.0.0.7 port 5001 connected with 16.0.0.1 port 40934 [ 6] local 16.0.0.7 port
5001 connected with 16.0.0.1 port 40930 [ 7] local 16.0.0.7 port 5001
connected with 16.0.0.1 port 40928 [ 8] local 16.0.0.7 port 5001 connected
with 16.0.0.1 port 40922 [ 9] local 16.0.0.7 port 5001 connected with 16.0.0.1
port 40932 [ 10] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40920
[ 11] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40924 [ 14] local
16.0.0.7 port 5001 connected with 16.0.0.1 port 40982 [ 12] local 16.0.0.7 port
5001 connected with 16.0.0.1 port 40980
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-20.0 sec 566 MBytes 237 Mbits/sec
[ 5] 0.0-20.0 sec 532 MBytes 223 Mbits/sec
[ 6] 0.0-20.0 sec 537 MBytes 225 Mbits/sec
[ 8] 0.0-20.0 sec 546 MBytes 229 Mbits/sec
[ 11] 0.0-20.0 sec 592 MBytes 248 Mbits/sec
[ 7] 0.0-20.0 sec 539 MBytes 226 Mbits/sec
[ 9] 0.0-20.0 sec 572 MBytes 240 Mbits/sec
[ 10] 0.0-20.0 sec 604 MBytes 253 Mbits/sec
[ 14] 0.0-20.0 sec 567 MBytes 238 Mbits/sec
[ 12] 0.0-20.0 sec 511 MBytes 214 Mbits/sec
[SUM] 0.0-20.0 sec 5.44 GBytes 2.33 Gbits/sec
Test 2: with this patch:
[root@brm-snt1-03 net]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
TCP: request_sock_TCP: Possible SYN flooding on port 5001. Sending cookies.
Check SNMP counters.
[ 4] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46876 [ 5] local
16.0.0.7 port 5001 connected with 16.0.0.1 port 46874 [ 6] local 16.0.0.7 port
5001 connected with 16.0.0.1 port 46872 [ 7] local 16.0.0.7 port 5001
connected with 16.0.0.1 port 46880 [ 8] local 16.0.0.7 port 5001 connected
with 16.0.0.1 port 46878 [ 9] local 16.0.0.7 port 5001 connected with 16.0.0.1
port 46884 [ 10] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46886
[ 11] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46890 [ 12] local
16.0.0.7 port 5001 connected with 16.0.0.1 port 46888 [ 13] local 16.0.0.7 port
5001 connected with 16.0.0.1 port 46882
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-20.0 sec 7.45 GBytes 3.19 Gbits/sec [ 5] 0.0-20.0 sec 7.48
GBytes 3.21 Gbits/sec [ 7] 0.0-20.0 sec 7.34 GBytes 3.15 Gbits/sec
[ 8] 0.0-20.0 sec 7.42 GBytes 3.18 Gbits/sec [ 9] 0.0-20.0 sec 7.24
GBytes 3.11 Gbits/sec [ 10] 0.0-20.0 sec 7.40 GBytes 3.17 Gbits/sec
[ 12] 0.0-20.0 sec 7.49 GBytes 3.21 Gbits/sec [ 6] 0.0-20.0 sec 7.30
GBytes 3.13 Gbits/sec [ 11] 0.0-20.0 sec 7.44 GBytes 3.19 Gbits/sec
[ 13] 0.0-20.0 sec 7.22 GBytes 3.10 Gbits/sec [SUM] 0.0-20.0 sec 73.8
GBytes 31.6 Gbits/sec
NOTE: In my testing, this patch does _not_ show any harm to i40e performance
numbers on x86.
Signed-off-by: Tushar Dave <tushar.n.d...@oracle.com>
---
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 69
++++++++++++++++++++--------- drivers/net/ethernet/intel/i40e/i40e_txrx.h |
1 +
2 files changed, 49 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 6287bf6..800dca7 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -551,15 +551,17 @@ static void
i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
else
dev_kfree_skb_any(tx_buffer->skb);
if (dma_unmap_len(tx_buffer, len))
- dma_unmap_single(ring->dev,
- dma_unmap_addr(tx_buffer, dma),
- dma_unmap_len(tx_buffer, len),
- DMA_TO_DEVICE);
+ dma_unmap_single_attrs(ring->dev,
+ dma_unmap_addr(tx_buffer, dma),
+ dma_unmap_len(tx_buffer, len),
+ DMA_TO_DEVICE,
+ ring->dma_attrs);
} else if (dma_unmap_len(tx_buffer, len)) {
- dma_unmap_page(ring->dev,
- dma_unmap_addr(tx_buffer, dma),
- dma_unmap_len(tx_buffer, len),
- DMA_TO_DEVICE);
+ dma_unmap_single_attrs(ring->dev,
+ dma_unmap_addr(tx_buffer, dma),
+ dma_unmap_len(tx_buffer, len),
+ DMA_TO_DEVICE,
+ ring->dma_attrs);
}
tx_buffer->next_to_watch = NULL;
@@ -662,6 +664,8 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
struct i40e_tx_buffer *tx_buf;
struct i40e_tx_desc *tx_head;
struct i40e_tx_desc *tx_desc;
+ dma_addr_t addr;
+ size_t size;
unsigned int total_bytes = 0, total_packets = 0;
unsigned int budget = vsi->work_limit;
@@ -696,10 +700,11 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
napi_consume_skb(tx_buf->skb, napi_budget);
/* unmap skb header data */
- dma_unmap_single(tx_ring->dev,
- dma_unmap_addr(tx_buf, dma),
- dma_unmap_len(tx_buf, len),
- DMA_TO_DEVICE);
+ dma_unmap_single_attrs(tx_ring->dev,
+ dma_unmap_addr(tx_buf, dma),
+ dma_unmap_len(tx_buf, len),
+ DMA_TO_DEVICE,
+ tx_ring->dma_attrs);
/* clear tx_buffer data */
tx_buf->skb = NULL;
@@ -717,12 +722,15 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
tx_desc = I40E_TX_DESC(tx_ring, 0);
}
+ addr = dma_unmap_addr(tx_buf, dma);
+ size = dma_unmap_len(tx_buf, len);
/* unmap any remaining paged data */
if (dma_unmap_len(tx_buf, len)) {
- dma_unmap_page(tx_ring->dev,
- dma_unmap_addr(tx_buf, dma),
- dma_unmap_len(tx_buf, len),
- DMA_TO_DEVICE);
+ dma_unmap_single_attrs(tx_ring->dev,
+ addr,
+ size,
+ DMA_TO_DEVICE,
+ tx_ring->dma_attrs);
dma_unmap_len_set(tx_buf, len, 0);
}
}
@@ -1010,6 +1018,11 @@ int i40e_setup_tx_descriptors(struct i40e_ring
*tx_ring)
*/
tx_ring->size += sizeof(u32);
tx_ring->size = ALIGN(tx_ring->size, 4096);
+#ifdef CONFIG_SPARC
+ tx_ring->dma_attrs = DMA_ATTR_WEAK_ORDERING; #else
+ tx_ring->dma_attrs = 0;
+#endif
tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
&tx_ring->dma, GFP_KERNEL);
if (!tx_ring->desc) {
@@ -1053,7 +1066,11 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
if (!rx_bi->page)
continue;
- dma_unmap_page(dev, rx_bi->dma, PAGE_SIZE,
DMA_FROM_DEVICE);
+ dma_unmap_single_attrs(dev,
+ rx_bi->dma,
+ PAGE_SIZE,
+ DMA_FROM_DEVICE,
+ rx_ring->dma_attrs);
__free_pages(rx_bi->page, 0);
rx_bi->page = NULL;
@@ -1113,6 +1130,11 @@ int i40e_setup_rx_descriptors(struct i40e_ring
*rx_ring)
/* Round up to nearest 4K */
rx_ring->size = rx_ring->count * sizeof(union i40e_32byte_rx_desc);
rx_ring->size = ALIGN(rx_ring->size, 4096);
+#ifdef CONFIG_SPARC
+ rx_ring->dma_attrs = DMA_ATTR_WEAK_ORDERING; #else
+ rx_ring->dma_attrs = 0;
+#endif
rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
&rx_ring->dma, GFP_KERNEL);
@@ -1182,7 +1204,8 @@ static bool i40e_alloc_mapped_page(struct
i40e_ring *rx_ring,
}
/* map page for use */
- dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE,
DMA_FROM_DEVICE);
+ dma = dma_map_single_attrs(rx_ring->dev, page_address(page),
PAGE_SIZE,
+ DMA_FROM_DEVICE, rx_ring->dma_attrs);
/* if mapping failed free memory back to system since
* there isn't much point in holding memory we can't use @@ -1695,8
+1718,11 @@ struct sk_buff *i40e_fetch_rx_buffer(struct i40e_ring *rx_ring,
rx_ring->rx_stats.page_reuse_count++;
} else {
/* we are not reusing the buffer so unmap it */
- dma_unmap_page(rx_ring->dev, rx_buffer->dma, PAGE_SIZE,
- DMA_FROM_DEVICE);
+ dma_unmap_single_attrs(rx_ring->dev,
+ rx_buffer->dma,
+ PAGE_SIZE,
+ DMA_FROM_DEVICE,
+ rx_ring->dma_attrs);
}
/* clear contents of buffer_info */
@@ -2737,7 +2763,8 @@ static inline void i40e_tx_map(struct i40e_ring
*tx_ring, struct sk_buff *skb,
first->skb = skb;
first->tx_flags = tx_flags;
- dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
+ dma = dma_map_single_attrs(tx_ring->dev, skb->data, size,
+ DMA_TO_DEVICE, tx_ring->dma_attrs);
tx_desc = I40E_TX_DESC(tx_ring, i);
tx_bi = first;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 5088405..9a86212 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -327,6 +327,7 @@ struct i40e_ring {
unsigned int size; /* length of descriptor ring in bytes */
dma_addr_t dma; /* physical address of ring */
+ unsigned long dma_attrs; /* DMA attributes */
struct i40e_vsi *vsi; /* Backreference to associated VSI */
struct i40e_q_vector *q_vector; /* Backreference to associated vector
*/
--
1.9.1
