[PATCH net-next v2] net: skbuff: optimization of net_zcopy_get() call in pskb_carve helpers
From: Yun Lu <hidden>
Date: 2026-07-08 05:55:52
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Yun Lu <redacted>
Commit 98d0912e9f84 ("net: skbuff: fix missing zerocopy reference in
pskb_carve helpers") introduced two calls of net_zcopy_get(skb_zcopy(skb)).
In fact, skb_zcopy() has already been executed once before. When calling
net_zcopy_get(), skb_zcopy() always returns skb_uarg(skb), which results
in adding some unnecessary instructions in skb_zcopy. So, change these
two calls to directly use skb_uarg(skb) instead of skb_zcopy.
In addition, also use net_zcopy_get() instead of refcount_inc() in
pskb_expand_head() for code consistency.
No functional change intended.
Signed-off-by: Yun Lu <redacted>
---
Changes in v2:
- Directly use skb_uarg(skb) instead of skb_zcopy.
Thanks: Willem de Bruijn
- Links to v1: https://lore.kernel.org/all/20260706100229.13812-1-luyun_611@163.com/ (local)
---
net/core/skbuff.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 18dabb4e9cfa..d798fbdc3da7 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -2326,7 +2326,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, if (skb_orphan_frags(skb, gfp_mask)) goto nofrags; if (skb_zcopy(skb)) - refcount_inc(&skb_uarg(skb)->refcnt); + net_zcopy_get(skb_uarg(skb)); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) skb_frag_ref(skb, i);
@@ -6842,7 +6842,7 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, return -ENOMEM; } if (skb_zcopy(skb)) - net_zcopy_get(skb_zcopy(skb)); + net_zcopy_get(skb_uarg(skb)); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) skb_frag_ref(skb, i); if (skb_has_frag_list(skb))
@@ -6992,7 +6992,7 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, return -ENOMEM; } if (skb_zcopy(skb)) - net_zcopy_get(skb_zcopy(skb)); + net_zcopy_get(skb_uarg(skb)); skb_release_data(skb, SKB_CONSUMED); skb->head = data;
--
2.43.0