[PATCH net-next v6 6/6] net: veth: use newly added page pool API for veth with xdp

From: Yunsheng Lin
Date: Mon Aug 14 2023 - 09:00:46 EST


Use page_pool[_cache]_alloc() API to allocate memory with
least memory utilization and performance penalty.

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
CC: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
CC: Alexander Duyck <alexander.duyck@xxxxxxxxx>
CC: Liang Chen <liangchen.linux@xxxxxxxxx>
CC: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
---
drivers/net/veth.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 953f6d8f8db0..aaef234be0d8 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -736,10 +736,11 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
if (skb_shared(skb) || skb_head_is_locked(skb) ||
skb_shinfo(skb)->nr_frags ||
skb_headroom(skb) < XDP_PACKET_HEADROOM) {
- u32 size, len, max_head_size, off;
+ u32 size, len, max_head_size, off, truesize, page_offset;
struct sk_buff *nskb;
struct page *page;
int i, head_off;
+ void *data;

/* We need a private copy of the skb and data buffers since
* the ebpf program can modify it. We segment the original skb
@@ -752,14 +753,17 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
goto drop;

+ size = min_t(u32, skb->len, max_head_size);
+ truesize = SKB_HEAD_ALIGN(size) + VETH_XDP_HEADROOM;
+
/* Allocate skb head */
- page = page_pool_dev_alloc_pages(rq->page_pool);
- if (!page)
+ data = page_pool_dev_cache_alloc(rq->page_pool, &truesize);
+ if (!data)
goto drop;

- nskb = napi_build_skb(page_address(page), PAGE_SIZE);
+ nskb = napi_build_skb(data, truesize);
if (!nskb) {
- page_pool_put_full_page(rq->page_pool, page, true);
+ page_pool_cache_free(rq->page_pool, data, true);
goto drop;
}

@@ -767,7 +771,6 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
skb_copy_header(nskb, skb);
skb_mark_for_recycle(nskb);

- size = min_t(u32, skb->len, max_head_size);
if (skb_copy_bits(skb, 0, nskb->data, size)) {
consume_skb(nskb);
goto drop;
@@ -782,14 +785,17 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
len = skb->len - off;

for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
- page = page_pool_dev_alloc_pages(rq->page_pool);
+ size = min_t(u32, len, PAGE_SIZE);
+ truesize = size;
+
+ page = page_pool_dev_alloc(rq->page_pool, &page_offset,
+ &truesize);
if (!page) {
consume_skb(nskb);
goto drop;
}

- size = min_t(u32, len, PAGE_SIZE);
- skb_add_rx_frag(nskb, i, page, 0, size, PAGE_SIZE);
+ skb_add_rx_frag(nskb, i, page, page_offset, size, truesize);
if (skb_copy_bits(skb, off, page_address(page),
size)) {
consume_skb(nskb);
--
2.33.0