[PATCH net-next 7/7] skbuff: remove unused skb->pp_recycle

From: Yunsheng Lin
Date: Wed Sep 22 2021 - 05:43:24 EST


As we have used pp_magic to identify pp page for the head
and frag page of a skb, the skb->pp_recycle is not used, so
remove it.

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
.../net/ethernet/hisilicon/hns3/hns3_enet.c | 6 ------
drivers/net/ethernet/marvell/mvneta.c | 2 --
.../net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 +---
drivers/net/ethernet/ti/cpsw.c | 2 --
drivers/net/ethernet/ti/cpsw_new.c | 2 --
include/linux/skbuff.h | 12 +----------
net/core/skbuff.c | 21 +------------------
7 files changed, 3 insertions(+), 46 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 22af3d6ce178..5331e0f2cee4 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -3864,9 +3864,6 @@ static int hns3_alloc_skb(struct hns3_enet_ring *ring, unsigned int length,
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);
@@ -3906,9 +3903,6 @@ static int hns3_add_frag(struct hns3_enet_ring *ring)
return -ENXIO;
}

- if (ring->page_pool)
- skb_mark_for_recycle(new_skb);
-
ring->frag_num = 0;

if (ring->tail_skb) {
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 9d460a270601..c852e0dd6d38 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2327,8 +2327,6 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
if (!skb)
return ERR_PTR(-ENOMEM);

- skb_mark_for_recycle(skb);
-
skb_reserve(skb, xdp->data - xdp->data_hard_start);
skb_put(skb, xdp->data_end - xdp->data);
skb->ip_summed = mvneta_rx_csum(pp, desc_status);
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index d5c92e43f89e..bacae115c6c6 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -3994,9 +3994,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
goto err_drop_frame;
}

- if (pp)
- skb_mark_for_recycle(skb);
- else
+ if (!pp)
dma_unmap_single_attrs(dev->dev.parent, dma_addr,
bm_pool->buf_size, DMA_FROM_DEVICE,
DMA_ATTR_SKIP_CPU_SYNC);
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 66f7ddd9b1f9..2fb5a4545b8b 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -430,8 +430,6 @@ static void cpsw_rx_handler(void *token, int len, int status)
cpts_rx_timestamp(cpsw->cpts, skb);
skb->protocol = eth_type_trans(skb, ndev);

- /* mark skb for recycling */
- 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 7968f24d99c8..1e74d484852d 100644
--- a/drivers/net/ethernet/ti/cpsw_new.c
+++ b/drivers/net/ethernet/ti/cpsw_new.c
@@ -374,8 +374,6 @@ static void cpsw_rx_handler(void *token, int len, int status)
cpts_rx_timestamp(cpsw->cpts, skb);
skb->protocol = eth_type_trans(skb, ndev);

- /* mark skb for recycling */
- 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 b77ee060b64d..d4bb0e160fef 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -668,8 +668,6 @@ typedef unsigned char *sk_buff_data_t;
* @head_frag: skb was allocated from page fragments,
* not allocated by kmalloc() or vmalloc().
* @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
- * @pp_recycle: mark the packet for recycling instead of freeing (implies
- * page_pool support on driver)
* @active_extensions: active extensions (skb_ext_id types)
* @ndisc_nodetype: router type (from link layer)
* @ooo_okay: allow the mapping of a socket to a queue to be changed
@@ -795,8 +793,7 @@ struct sk_buff {
fclone:2,
peeked:1,
head_frag:1,
- pfmemalloc:1,
- pp_recycle:1; /* page_pool recycle indicator */
+ pfmemalloc:1;
#ifdef CONFIG_SKB_EXTENSIONS
__u8 active_extensions;
#endif
@@ -4721,12 +4718,5 @@ static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
#endif
}

-#ifdef CONFIG_PAGE_POOL
-static inline void skb_mark_for_recycle(struct sk_buff *skb)
-{
- skb->pp_recycle = 1;
-}
-#endif
-
#endif /* __KERNEL__ */
#endif /* _LINUX_SKBUFF_H */
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 3718898da499..85ae59f4349a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -670,7 +670,7 @@ static void skb_release_data(struct sk_buff *skb)
if (skb->cloned &&
atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
&shinfo->dataref))
- goto exit;
+ return;

skb_zcopy_clear(skb, true);

@@ -681,17 +681,6 @@ static void skb_release_data(struct sk_buff *skb)
kfree_skb_list(shinfo->frag_list);

skb_free_head(skb);
-exit:
- /* When we clone an SKB we copy the reycling bit. The pp_recycle
- * bit is only set on the head though, so in order to avoid races
- * while trying to recycle fragments on __skb_frag_unref() we need
- * to make one SKB responsible for triggering the recycle path.
- * So disable the recycling bit if an SKB is cloned and we have
- * additional references to to the fragmented part of the SKB.
- * Eventually the last SKB will have the recycling bit set and it's
- * dataref set to 0, which will trigger the recycling
- */
- skb->pp_recycle = 0;
}

/*
@@ -1073,7 +1062,6 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
n->nohdr = 0;
n->peeked = 0;
C(pfmemalloc);
- C(pp_recycle);
n->destructor = NULL;
C(tail);
C(end);
@@ -5368,13 +5356,6 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
if (skb_cloned(to))
return false;

- /* The page pool signature of struct page will eventually figure out
- * which pages can be recycled or not but for now let's prohibit slab
- * allocated and page_pool allocated SKBs from being coalesced.
- */
- if (to->pp_recycle != from->pp_recycle)
- return false;
-
if (len <= skb_tailroom(to)) {
if (len)
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
--
2.33.0