[PATCH net-next] net: mana: Add page pool for RX buffers
From: Haiyang Zhang <haiyangz@microsoft.com>
Date: 2023-07-13 14:49:02
Also in:
bpf, linux-hyperv, linux-rdma, lkml
Subsystem:
hyper-v/azure core and drivers, networking drivers, networking [general], the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add page pool for RX buffers for faster buffer cycle and reduce CPU usage. Get an extra ref count of a page after allocation, so after upper layers put the page, it's still referenced by the pool. We can reuse it as RX buffer without alloc a new page. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> --- drivers/net/ethernet/microsoft/mana/mana_en.c | 73 ++++++++++++++++++- include/net/mana/mana.h | 5 ++ 2 files changed, 77 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index a499e460594b..6444a8e47852 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c@@ -1507,6 +1507,34 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe, return; } +static struct page *mana_get_page_from_pool(struct mana_rxq *rxq) +{ + struct page *page; + int i; + + i = rxq->pl_last + 1; + if (i >= MANA_POOL_SIZE) + i = 0; + + rxq->pl_last = i; + + page = rxq->pool[i]; + if (page_ref_count(page) == 1) { + get_page(page); + return page; + } + + page = dev_alloc_page(); + if (page) { + put_page(rxq->pool[i]); + + get_page(page); + rxq->pool[i] = page; + } + + return page; +} + static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev, dma_addr_t *da, bool is_napi) {
@@ -1533,7 +1561,7 @@ static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev, return NULL; } } else { - page = dev_alloc_page(); + page = mana_get_page_from_pool(rxq); if (!page) return NULL;
@@ -1873,6 +1901,21 @@ static int mana_create_txq(struct mana_port_context *apc, return err; } +static void mana_release_rxq_pool(struct mana_rxq *rxq) +{ + struct page *page; + int i; + + for (i = 0; i < MANA_POOL_SIZE; i++) { + page = rxq->pool[i]; + + if (page) + put_page(page); + + rxq->pool[i] = NULL; + } +} + static void mana_destroy_rxq(struct mana_port_context *apc, struct mana_rxq *rxq, bool validate_state)
@@ -1917,6 +1960,8 @@ static void mana_destroy_rxq(struct mana_port_context *apc, rx_oob->buf_va = NULL; } + mana_release_rxq_pool(rxq); + if (rxq->gdma_rq) mana_gd_destroy_queue(gc, rxq->gdma_rq);
@@ -2008,6 +2053,27 @@ static int mana_push_wqe(struct mana_rxq *rxq) return 0; } +static int mana_alloc_rxq_pool(struct mana_rxq *rxq) +{ + struct page *page; + int i; + + for (i = 0; i < MANA_POOL_SIZE; i++) { + page = dev_alloc_page(); + if (!page) + goto err; + + rxq->pool[i] = page; + } + + return 0; + +err: + mana_release_rxq_pool(rxq); + + return -ENOMEM; +} + static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc, u32 rxq_idx, struct mana_eq *eq, struct net_device *ndev)
@@ -2029,6 +2095,11 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc, if (!rxq) return NULL; + if (mana_alloc_rxq_pool(rxq)) { + kfree(rxq); + return NULL; + } + rxq->ndev = ndev; rxq->num_rx_buf = RX_BUFFERS_PER_QUEUE; rxq->rxq_idx = rxq_idx;
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 024ad8ddb27e..8f1f09f9e4ab 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h@@ -297,6 +297,8 @@ struct mana_recv_buf_oob { #define MANA_XDP_MTU_MAX (PAGE_SIZE - MANA_RXBUF_PAD - XDP_PACKET_HEADROOM) +#define MANA_POOL_SIZE (RX_BUFFERS_PER_QUEUE * 2) + struct mana_rxq { struct gdma_queue *gdma_rq; /* Cache the gdma receive queue id */
@@ -330,6 +332,9 @@ struct mana_rxq { bool xdp_flush; int xdp_rc; /* XDP redirect return code */ + struct page *pool[MANA_POOL_SIZE]; + int pl_last; + /* MUST BE THE LAST MEMBER: * Each receive buffer has an associated mana_recv_buf_oob. */
--
2.25.1