[PATCH rfc v4 1/4] page_pool: keep pp info as long as page pool owns the page

From: Yunsheng Lin
Date: Tue Jul 13 2021 - 05:25:24 EST


Currently, page->pp is cleared and set everytime the page
is recycled, which is unnecessary.

So only set the page->pp when the page is added to the page
pool and only clear it when the page is released from the
page pool.

This is also a preparation to support allocating frag page
in page pool.

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
drivers/net/ethernet/marvell/mvneta.c | 6 +-----
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +-
drivers/net/ethernet/ti/cpsw.c | 2 +-
drivers/net/ethernet/ti/cpsw_new.c | 2 +-
include/linux/skbuff.h | 4 +---
include/net/page_pool.h | 7 -------
net/core/page_pool.c | 21 +++++++++++++++++----
7 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 361bc4f..89bf31fd 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2327,7 +2327,7 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
if (!skb)
return ERR_PTR(-ENOMEM);

- skb_mark_for_recycle(skb, virt_to_page(xdp->data), pool);
+ skb_mark_for_recycle(skb);

skb_reserve(skb, xdp->data - xdp->data_hard_start);
skb_put(skb, xdp->data_end - xdp->data);
@@ -2339,10 +2339,6 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
skb_frag_page(frag), skb_frag_off(frag),
skb_frag_size(frag), PAGE_SIZE);
- /* We don't need to reset pp_recycle here. It's already set, so
- * just mark fragments for recycling.
- */
- page_pool_store_mem_info(skb_frag_page(frag), pool);
}

return skb;
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 3229baf..320eddb 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -3995,7 +3995,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
}

if (pp)
- skb_mark_for_recycle(skb, page, pp);
+ skb_mark_for_recycle(skb);
else
dma_unmap_single_attrs(dev->dev.parent, dma_addr,
bm_pool->buf_size, DMA_FROM_DEVICE,
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index cbbd0f6..9d59143 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -431,7 +431,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
skb->protocol = eth_type_trans(skb, ndev);

/* mark skb for recycling */
- skb_mark_for_recycle(skb, page, pool);
+ skb_mark_for_recycle(skb);
netif_receive_skb(skb);

ndev->stats.rx_bytes += len;
diff --git a/drivers/net/ethernet/ti/cpsw_new.c b/drivers/net/ethernet/ti/cpsw_new.c
index 57d279f..a4234a3 100644
--- a/drivers/net/ethernet/ti/cpsw_new.c
+++ b/drivers/net/ethernet/ti/cpsw_new.c
@@ -374,7 +374,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
skb->protocol = eth_type_trans(skb, ndev);

/* mark skb for recycling */
- skb_mark_for_recycle(skb, page, pool);
+ skb_mark_for_recycle(skb);
netif_receive_skb(skb);

ndev->stats.rx_bytes += len;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b2db9cd..7795979 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4711,11 +4711,9 @@ static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
}

#ifdef CONFIG_PAGE_POOL
-static inline void skb_mark_for_recycle(struct sk_buff *skb, struct page *page,
- struct page_pool *pp)
+static inline void skb_mark_for_recycle(struct sk_buff *skb)
{
skb->pp_recycle = 1;
- page_pool_store_mem_info(page, pp);
}
#endif

diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index 3dd62dd..8d7744d 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -253,11 +253,4 @@ static inline void page_pool_ring_unlock(struct page_pool *pool)
spin_unlock_bh(&pool->ring.producer_lock);
}

-/* Store mem_info on struct page and use it while recycling skb frags */
-static inline
-void page_pool_store_mem_info(struct page *page, struct page_pool *pp)
-{
- page->pp = pp;
-}
-
#endif /* _NET_PAGE_POOL_H */
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 5e4eb45..78838c6 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -206,6 +206,19 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
return true;
}

+static void page_pool_set_pp_info(struct page_pool *pool,
+ struct page *page)
+{
+ page->pp = pool;
+ page->pp_magic |= PP_SIGNATURE;
+}
+
+static void page_pool_clear_pp_info(struct page *page)
+{
+ page->pp_magic = 0;
+ page->pp = NULL;
+}
+
static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
gfp_t gfp)
{
@@ -222,7 +235,7 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
return NULL;
}

- page->pp_magic |= PP_SIGNATURE;
+ page_pool_set_pp_info(pool, page);

/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
@@ -266,7 +279,8 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
put_page(page);
continue;
}
- page->pp_magic |= PP_SIGNATURE;
+
+ page_pool_set_pp_info(pool, page);
pool->alloc.cache[pool->alloc.count++] = page;
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
@@ -345,7 +359,7 @@ void page_pool_release_page(struct page_pool *pool, struct page *page)
DMA_ATTR_SKIP_CPU_SYNC);
page_pool_set_dma_addr(page, 0);
skip_dma_unmap:
- page->pp_magic = 0;
+ page_pool_clear_pp_info(page);

/* This may be the last page returned, releasing the pool, so
* it is not safe to reference pool afterwards.
@@ -644,7 +658,6 @@ bool page_pool_return_skb_page(struct page *page)
* The page will be returned to the pool here regardless of the
* 'flipped' fragment being in use or not.
*/
- page->pp = NULL;
page_pool_put_full_page(pp, page, false);

return true;
--
2.7.4