diff mbox series

[lunar,linux-azure] net: mana: Add page pool for RX buffers

Message ID 20230905182110.78672-3-tim.gardner@canonical.com
State New
Headers show
Series [lunar,linux-azure] net: mana: Add page pool for RX buffers | expand

Commit Message

Tim Gardner Sept. 5, 2023, 6:21 p.m. UTC
From: Haiyang Zhang <haiyangz@microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/2034277

Add page pool for RX buffers for faster buffer cycle and reduce CPU
usage.

The standard page pool API is used.

With iperf and 128 threads test, this patch improved the throughput
by 12-15%, and decreased the IRQ associated CPU's usage from 99-100% to
10-50%.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit b1d13f7a3b5396503e6869ed627bb4eeab9b524f)
[rtg - dropped pprm.napi since that field hasn't been invented for 6.2]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 89 +++++++++++++++----
 include/net/mana/mana.h                       |  3 +
 2 files changed, 76 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 146b4f99a5d8..82ccee55b2b7 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1411,8 +1411,8 @@  static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
 	return skb;
 }
 
-static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
-			struct mana_rxq *rxq)
+static void mana_rx_skb(void *buf_va, bool from_pool,
+			struct mana_rxcomp_oob *cqe, struct mana_rxq *rxq)
 {
 	struct mana_stats_rx *rx_stats = &rxq->stats;
 	struct net_device *ndev = rxq->ndev;
@@ -1445,6 +1445,9 @@  static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
 	if (!skb)
 		goto drop;
 
+	if (from_pool)
+		skb_mark_for_recycle(skb);
+
 	skb->dev = napi->dev;
 
 	skb->protocol = eth_type_trans(skb, ndev);
@@ -1495,9 +1498,14 @@  static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
 	u64_stats_update_end(&rx_stats->syncp);
 
 drop:
-	WARN_ON_ONCE(rxq->xdp_save_va);
-	/* Save for reuse */
-	rxq->xdp_save_va = buf_va;
+	if (from_pool) {
+		page_pool_recycle_direct(rxq->page_pool,
+					 virt_to_head_page(buf_va));
+	} else {
+		WARN_ON_ONCE(rxq->xdp_save_va);
+		/* Save for reuse */
+		rxq->xdp_save_va = buf_va;
+	}
 
 	++ndev->stats.rx_dropped;
 
@@ -1505,11 +1513,13 @@  static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
 }
 
 static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
-			     dma_addr_t *da, bool is_napi)
+			     dma_addr_t *da, bool *from_pool, bool is_napi)
 {
 	struct page *page;
 	void *va;
 
+	*from_pool = false;
+
 	/* Reuse XDP dropped page if available */
 	if (rxq->xdp_save_va) {
 		va = rxq->xdp_save_va;
@@ -1530,17 +1540,22 @@  static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
 			return NULL;
 		}
 	} else {
-		page = dev_alloc_page();
+		page = page_pool_dev_alloc_pages(rxq->page_pool);
 		if (!page)
 			return NULL;
 
+		*from_pool = true;
 		va = page_to_virt(page);
 	}
 
 	*da = dma_map_single(dev, va + rxq->headroom, rxq->datasize,
 			     DMA_FROM_DEVICE);
 	if (dma_mapping_error(dev, *da)) {
-		put_page(virt_to_head_page(va));
+		if (*from_pool)
+			page_pool_put_full_page(rxq->page_pool, page, false);
+		else
+			put_page(virt_to_head_page(va));
+
 		return NULL;
 	}
 
@@ -1549,21 +1564,25 @@  static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
 
 /* Allocate frag for rx buffer, and save the old buf */
 static void mana_refill_rx_oob(struct device *dev, struct mana_rxq *rxq,
-			       struct mana_recv_buf_oob *rxoob, void **old_buf)
+			       struct mana_recv_buf_oob *rxoob, void **old_buf,
+			       bool *old_fp)
 {
+	bool from_pool;
 	dma_addr_t da;
 	void *va;
 
-	va = mana_get_rxfrag(rxq, dev, &da, true);
+	va = mana_get_rxfrag(rxq, dev, &da, &from_pool, true);
 	if (!va)
 		return;
 
 	dma_unmap_single(dev, rxoob->sgl[0].address, rxq->datasize,
 			 DMA_FROM_DEVICE);
 	*old_buf = rxoob->buf_va;
+	*old_fp = rxoob->from_pool;
 
 	rxoob->buf_va = va;
 	rxoob->sgl[0].address = da;
+	rxoob->from_pool = from_pool;
 }
 
 static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
@@ -1577,6 +1596,7 @@  static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	struct device *dev = gc->dev;
 	void *old_buf = NULL;
 	u32 curr, pktlen;
+	bool old_fp;
 
 	apc = netdev_priv(ndev);
 
@@ -1619,12 +1639,12 @@  static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	rxbuf_oob = &rxq->rx_oobs[curr];
 	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
 
-	mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf);
+	mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
 
 	/* Unsuccessful refill will have old_buf == NULL.
 	 * In this case, mana_rx_skb() will drop the packet.
 	 */
-	mana_rx_skb(old_buf, oob, rxq);
+	mana_rx_skb(old_buf, old_fp, oob, rxq);
 
 drop:
 	mana_move_wq_tail(rxq->gdma_rq, rxbuf_oob->wqe_inf.wqe_size_in_bu);
@@ -1884,6 +1904,7 @@  static void mana_destroy_rxq(struct mana_port_context *apc,
 	struct mana_recv_buf_oob *rx_oob;
 	struct device *dev = gc->dev;
 	struct napi_struct *napi;
+	struct page *page;
 	int i;
 
 	if (!rxq)
@@ -1916,10 +1937,18 @@  static void mana_destroy_rxq(struct mana_port_context *apc,
 		dma_unmap_single(dev, rx_oob->sgl[0].address,
 				 rx_oob->sgl[0].size, DMA_FROM_DEVICE);
 
-		put_page(virt_to_head_page(rx_oob->buf_va));
+		page = virt_to_head_page(rx_oob->buf_va);
+
+		if (rx_oob->from_pool)
+			page_pool_put_full_page(rxq->page_pool, page, false);
+		else
+			put_page(page);
+
 		rx_oob->buf_va = NULL;
 	}
 
+	page_pool_destroy(rxq->page_pool);
+
 	if (rxq->gdma_rq)
 		mana_gd_destroy_queue(gc, rxq->gdma_rq);
 
@@ -1930,18 +1959,20 @@  static int mana_fill_rx_oob(struct mana_recv_buf_oob *rx_oob, u32 mem_key,
 			    struct mana_rxq *rxq, struct device *dev)
 {
 	struct mana_port_context *mpc = netdev_priv(rxq->ndev);
+	bool from_pool = false;
 	dma_addr_t da;
 	void *va;
 
 	if (mpc->rxbufs_pre)
 		va = mana_get_rxbuf_pre(rxq, &da);
 	else
-		va = mana_get_rxfrag(rxq, dev, &da, false);
+		va = mana_get_rxfrag(rxq, dev, &da, &from_pool, false);
 
 	if (!va)
 		return -ENOMEM;
 
 	rx_oob->buf_va = va;
+	rx_oob->from_pool = from_pool;
 
 	rx_oob->sgl[0].address = da;
 	rx_oob->sgl[0].size = rxq->datasize;
@@ -2011,6 +2042,25 @@  static int mana_push_wqe(struct mana_rxq *rxq)
 	return 0;
 }
 
+static int mana_create_page_pool(struct mana_rxq *rxq, struct gdma_context *gc)
+{
+	struct page_pool_params pprm = {};
+	int ret;
+
+	pprm.pool_size = RX_BUFFERS_PER_QUEUE;
+	pprm.nid = gc->numa_node;
+
+	rxq->page_pool = page_pool_create(&pprm);
+
+	if (IS_ERR(rxq->page_pool)) {
+		ret = PTR_ERR(rxq->page_pool);
+		rxq->page_pool = NULL;
+		return ret;
+	}
+
+	return 0;
+}
+
 static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 					u32 rxq_idx, struct mana_eq *eq,
 					struct net_device *ndev)
@@ -2040,6 +2090,13 @@  static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 	mana_get_rxbuf_cfg(ndev->mtu, &rxq->datasize, &rxq->alloc_size,
 			   &rxq->headroom);
 
+	/* Create page pool for RX queue */
+	err = mana_create_page_pool(rxq, gc);
+	if (err) {
+		netdev_err(ndev, "Create page pool err:%d\n", err);
+		goto out;
+	}
+
 	err = mana_alloc_rx_wqe(apc, rxq, &rq_size, &cq_size);
 	if (err)
 		goto out;
@@ -2111,8 +2168,8 @@  static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 
 	WARN_ON(xdp_rxq_info_reg(&rxq->xdp_rxq, ndev, rxq_idx,
 				 cq->napi.napi_id));
-	WARN_ON(xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq,
-					   MEM_TYPE_PAGE_SHARED, NULL));
+	WARN_ON(xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq, MEM_TYPE_PAGE_POOL,
+					   rxq->page_pool));
 
 	napi_enable(&cq->napi);
 
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 9eef19972845..4a7fc0d6bbc9 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -280,6 +280,7 @@  struct mana_recv_buf_oob {
 	struct gdma_wqe_request wqe_req;
 
 	void *buf_va;
+	bool from_pool; /* allocated from a page pool */
 
 	/* SGL of the buffer going to be sent has part of the work request. */
 	u32 num_sge;
@@ -330,6 +331,8 @@  struct mana_rxq {
 	bool xdp_flush;
 	int xdp_rc; /* XDP redirect return code */
 
+	struct page_pool *page_pool;
+
 	/* MUST BE THE LAST MEMBER:
 	 * Each receive buffer has an associated mana_recv_buf_oob.
 	 */