diff mbox series

[net-next] skbuff: remove some unnecessary operation in skb_segment_list()

Message ID 1615364938-52943-1-git-send-email-linyunsheng@huawei.com (mailing list archive)
State Accepted
Commit 1ddc3229ad3c40840c24a699ada5cfeb4319b578
Delegated to: Netdev Maintainers
Headers show
Series [net-next] skbuff: remove some unnecessary operation in skb_segment_list() | expand

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Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/header_inline success Link

Commit Message

Yunsheng Lin March 10, 2021, 8:28 a.m. UTC 
From: Yunsheng Lin <linyunsheng@huawei.com>

gro list uses skb_shinfo(skb)->frag_list to link two skb together,
and NAPI_GRO_CB(p)->last->next is used when there are more skb,
see skb_gro_receive_list(). gso expects that each segmented skb is
linked together using skb->next, so only the first skb->next need
to set to skb_shinfo(skb)-> frag_list when doing gso list segment.

It is the same reason that nskb->next does not need to be set to
list_skb before goto the error handling, because nskb->next already
pointers to list_skb.

And nskb is also the last skb at the end of loop, so remove tail
variable and use nskb instead.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
---
 net/core/skbuff.c | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org March 10, 2021, 9 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Wed, 10 Mar 2021 16:28:58 +0800 you wrote:
> From: Yunsheng Lin <linyunsheng@huawei.com>
> 
> gro list uses skb_shinfo(skb)->frag_list to link two skb together,
> and NAPI_GRO_CB(p)->last->next is used when there are more skb,
> see skb_gro_receive_list(). gso expects that each segmented skb is
> linked together using skb->next, so only the first skb->next need
> to set to skb_shinfo(skb)-> frag_list when doing gso list segment.
> 
> [...]

Here is the summary with links:
  - [net-next] skbuff: remove some unnecessary operation in skb_segment_list()
    https://git.kernel.org/netdev/net-next/c/1ddc3229ad3c

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c421c8f..e8320b5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3732,13 +3732,13 @@  struct sk_buff *skb_segment_list(struct sk_buff *skb,
 	unsigned int tnl_hlen = skb_tnl_header_len(skb);
 	unsigned int delta_truesize = 0;
 	unsigned int delta_len = 0;
-	struct sk_buff *tail = NULL;
 	struct sk_buff *nskb, *tmp;
 	int err;
 
 	skb_push(skb, -skb_network_offset(skb) + offset);
 
 	skb_shinfo(skb)->frag_list = NULL;
+	skb->next = list_skb;
 
 	do {
 		nskb = list_skb;
@@ -3756,17 +3756,8 @@  struct sk_buff *skb_segment_list(struct sk_buff *skb,
 			}
 		}
 
-		if (!tail)
-			skb->next = nskb;
-		else
-			tail->next = nskb;
-
-		if (unlikely(err)) {
-			nskb->next = list_skb;
+		if (unlikely(err))
 			goto err_linearize;
-		}
-
-		tail = nskb;
 
 		delta_len += nskb->len;
 		delta_truesize += nskb->truesize;
@@ -3793,7 +3784,7 @@  struct sk_buff *skb_segment_list(struct sk_buff *skb,
 
 	skb_gso_reset(skb);
 
-	skb->prev = tail;
+	skb->prev = nskb;
 
 	if (skb_needs_linearize(skb, features) &&
 	    __skb_linearize(skb))