[PATCH net-next v2 4/4] net: hns3: support skb's frag page recycling based on page pool

From: Yunsheng Lin
Date: Thu Aug 05 2021 - 22:47:40 EST


This patch adds skb's frag page recycling support based on
the frag page support in page pool.

The performance improves above 10~20% for single thread iperf
TCP flow with IOMMU disabled when iperf server and irq/NAPI
have a different CPU.

The performance improves about 135%(14Gbit to 33Gbit) for single
thread iperf TCP flow when IOMMU is in strict mode and iperf
server shares the same cpu with irq/NAPI.

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
drivers/net/ethernet/hisilicon/Kconfig | 1 +
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 79 +++++++++++++++++++++++--
drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 3 +
3 files changed, 78 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/Kconfig b/drivers/net/ethernet/hisilicon/Kconfig
index 094e4a3..2ba0e7b 100644
--- a/drivers/net/ethernet/hisilicon/Kconfig
+++ b/drivers/net/ethernet/hisilicon/Kconfig
@@ -91,6 +91,7 @@ config HNS3
tristate "Hisilicon Network Subsystem Support HNS3 (Framework)"
depends on PCI
select NET_DEVLINK
+ select PAGE_POOL
help
This selects the framework support for Hisilicon Network Subsystem 3.
This layer facilitates clients like ENET, RoCE and user-space ethernet
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index cb8d5da..fcbeb1f 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -3205,6 +3205,21 @@ static int hns3_alloc_buffer(struct hns3_enet_ring *ring,
unsigned int order = hns3_page_order(ring);
struct page *p;

+ if (ring->page_pool) {
+ p = page_pool_dev_alloc_frag(ring->page_pool,
+ &cb->page_offset,
+ hns3_buf_size(ring));
+ if (unlikely(!p))
+ return -ENOMEM;
+
+ cb->priv = p;
+ cb->buf = page_address(p);
+ cb->dma = page_pool_get_dma_addr(p);
+ cb->type = DESC_TYPE_PP_FRAG;
+ cb->reuse_flag = 0;
+ return 0;
+ }
+
p = dev_alloc_pages(order);
if (!p)
return -ENOMEM;
@@ -3227,8 +3242,13 @@ static void hns3_free_buffer(struct hns3_enet_ring *ring,
if (cb->type & (DESC_TYPE_SKB | DESC_TYPE_BOUNCE_HEAD |
DESC_TYPE_BOUNCE_ALL | DESC_TYPE_SGL_SKB))
napi_consume_skb(cb->priv, budget);
- else if (!HNAE3_IS_TX_RING(ring) && cb->pagecnt_bias)
- __page_frag_cache_drain(cb->priv, cb->pagecnt_bias);
+ else if (!HNAE3_IS_TX_RING(ring)) {
+ if (cb->type & DESC_TYPE_PAGE && cb->pagecnt_bias)
+ __page_frag_cache_drain(cb->priv, cb->pagecnt_bias);
+ else if (cb->type & DESC_TYPE_PP_FRAG)
+ page_pool_put_full_page(ring->page_pool, cb->priv,
+ false);
+ }
memset(cb, 0, sizeof(*cb));
}

@@ -3315,7 +3335,7 @@ static int hns3_alloc_and_map_buffer(struct hns3_enet_ring *ring,
int ret;

ret = hns3_alloc_buffer(ring, cb);
- if (ret)
+ if (ret || ring->page_pool)
goto out;

ret = hns3_map_buffer(ring, cb);
@@ -3337,7 +3357,8 @@ static int hns3_alloc_and_attach_buffer(struct hns3_enet_ring *ring, int i)
if (ret)
return ret;

- ring->desc[i].addr = cpu_to_le64(ring->desc_cb[i].dma);
+ ring->desc[i].addr = cpu_to_le64(ring->desc_cb[i].dma +
+ ring->desc_cb[i].page_offset);

return 0;
}
@@ -3367,7 +3388,8 @@ static void hns3_replace_buffer(struct hns3_enet_ring *ring, int i,
{
hns3_unmap_buffer(ring, &ring->desc_cb[i]);
ring->desc_cb[i] = *res_cb;
- ring->desc[i].addr = cpu_to_le64(ring->desc_cb[i].dma);
+ ring->desc[i].addr = cpu_to_le64(ring->desc_cb[i].dma +
+ ring->desc_cb[i].page_offset);
ring->desc[i].rx.bd_base_info = 0;
}

@@ -3539,6 +3561,12 @@ static void hns3_nic_reuse_page(struct sk_buff *skb, int i,
u32 frag_size = size - pull_len;
bool reused;

+ if (ring->page_pool) {
+ skb_add_rx_frag(skb, i, desc_cb->priv, frag_offset,
+ frag_size, truesize);
+ return;
+ }
+
/* Avoid re-using remote or pfmem page */
if (unlikely(!dev_page_is_reusable(desc_cb->priv)))
goto out;
@@ -3856,6 +3884,9 @@ static int hns3_alloc_skb(struct hns3_enet_ring *ring, unsigned int length,
/* We can reuse buffer as-is, just make sure it is reusable */
if (dev_page_is_reusable(desc_cb->priv))
desc_cb->reuse_flag = 1;
+ else if (desc_cb->type & DESC_TYPE_PP_FRAG)
+ page_pool_put_full_page(ring->page_pool, desc_cb->priv,
+ false);
else /* This page cannot be reused so discard it */
__page_frag_cache_drain(desc_cb->priv,
desc_cb->pagecnt_bias);
@@ -3863,6 +3894,10 @@ static int hns3_alloc_skb(struct hns3_enet_ring *ring, unsigned int length,
hns3_rx_ring_move_fw(ring);
return 0;
}
+
+ if (ring->page_pool)
+ skb_mark_for_recycle(skb);
+
u64_stats_update_begin(&ring->syncp);
ring->stats.seg_pkt_cnt++;
u64_stats_update_end(&ring->syncp);
@@ -3901,6 +3936,10 @@ static int hns3_add_frag(struct hns3_enet_ring *ring)
"alloc rx fraglist skb fail\n");
return -ENXIO;
}
+
+ if (ring->page_pool)
+ skb_mark_for_recycle(new_skb);
+
ring->frag_num = 0;

if (ring->tail_skb) {
@@ -4705,6 +4744,29 @@ static void hns3_put_ring_config(struct hns3_nic_priv *priv)
priv->ring = NULL;
}

+static void hns3_alloc_page_pool(struct hns3_enet_ring *ring)
+{
+ struct page_pool_params pp_params = {
+ .flags = PP_FLAG_DMA_MAP | PP_FLAG_PAGE_FRAG |
+ PP_FLAG_DMA_SYNC_DEV,
+ .order = hns3_page_order(ring),
+ .pool_size = ring->desc_num * hns3_buf_size(ring) /
+ (PAGE_SIZE << hns3_page_order(ring)),
+ .nid = dev_to_node(ring_to_dev(ring)),
+ .dev = ring_to_dev(ring),
+ .dma_dir = DMA_FROM_DEVICE,
+ .offset = 0,
+ .max_len = PAGE_SIZE << hns3_page_order(ring),
+ };
+
+ ring->page_pool = page_pool_create(&pp_params);
+ if (IS_ERR(ring->page_pool)) {
+ dev_warn(ring_to_dev(ring), "page pool creation failed: %ld\n",
+ PTR_ERR(ring->page_pool));
+ ring->page_pool = NULL;
+ }
+}
+
static int hns3_alloc_ring_memory(struct hns3_enet_ring *ring)
{
int ret;
@@ -4724,6 +4786,8 @@ static int hns3_alloc_ring_memory(struct hns3_enet_ring *ring)
goto out_with_desc_cb;

if (!HNAE3_IS_TX_RING(ring)) {
+ hns3_alloc_page_pool(ring);
+
ret = hns3_alloc_ring_buffers(ring);
if (ret)
goto out_with_desc;
@@ -4764,6 +4828,11 @@ void hns3_fini_ring(struct hns3_enet_ring *ring)
devm_kfree(ring_to_dev(ring), tx_spare);
ring->tx_spare = NULL;
}
+
+ if (!HNAE3_IS_TX_RING(ring) && ring->page_pool) {
+ page_pool_destroy(ring->page_pool);
+ ring->page_pool = NULL;
+ }
}

static int hns3_buf_size2type(u32 buf_size)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
index 15af3d9..27809d6 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -6,6 +6,7 @@

#include <linux/dim.h>
#include <linux/if_vlan.h>
+#include <net/page_pool.h>

#include "hnae3.h"

@@ -307,6 +308,7 @@ enum hns3_desc_type {
DESC_TYPE_BOUNCE_ALL = 1 << 3,
DESC_TYPE_BOUNCE_HEAD = 1 << 4,
DESC_TYPE_SGL_SKB = 1 << 5,
+ DESC_TYPE_PP_FRAG = 1 << 6,
};

struct hns3_desc_cb {
@@ -451,6 +453,7 @@ struct hns3_enet_ring {
struct hnae3_queue *tqp;
int queue_index;
struct device *dev; /* will be used for DMA mapping of descriptors */
+ struct page_pool *page_pool;

/* statistic */
struct ring_stats stats;
--
2.7.4