* [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail()
@ 2017-07-06 9:01 Lin Zhang
2017-07-06 9:16 ` Eric Dumazet
0 siblings, 1 reply; 5+ messages in thread
From: Lin Zhang @ 2017-07-06 9:01 UTC (permalink / raw)
To: davem; +Cc: linux-kernel, netdev, Lin Zhang
In the pull_pages code block, if the first frags size > eat,
we can end the loop in advance to avoid extra copy.
Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
---
net/core/skbuff.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f990eb8..c00a1df 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1720,6 +1720,10 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta)
skb_shinfo(skb)->frags[k].page_offset += eat;
skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
eat = 0;
+ if (!i) {
+ k = skb_shinfo(skb)->nr_frags;
+ break;
+ }
}
k++;
}
--
1.8.3.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail()
2017-07-06 9:01 [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail() Lin Zhang
@ 2017-07-06 9:16 ` Eric Dumazet
2017-07-06 9:23 ` Eric Dumazet
0 siblings, 1 reply; 5+ messages in thread
From: Eric Dumazet @ 2017-07-06 9:16 UTC (permalink / raw)
To: Lin Zhang; +Cc: davem, linux-kernel, netdev
On Thu, 2017-07-06 at 17:01 +0800, Lin Zhang wrote:
> In the pull_pages code block, if the first frags size > eat,
> we can end the loop in advance to avoid extra copy.
>
> Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
> ---
> net/core/skbuff.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index f990eb8..c00a1df 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -1720,6 +1720,10 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta)
> skb_shinfo(skb)->frags[k].page_offset += eat;
> skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
> eat = 0;
> + if (!i) {
> + k = skb_shinfo(skb)->nr_frags;
> + break;
> + }
> }
> k++;
> }
1) net-next is closed during merge window.
2) This change is completely buggy.
How have you tested it exactly ???
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail()
2017-07-06 9:16 ` Eric Dumazet
@ 2017-07-06 9:23 ` Eric Dumazet
2017-07-06 9:35 ` lin zhang
0 siblings, 1 reply; 5+ messages in thread
From: Eric Dumazet @ 2017-07-06 9:23 UTC (permalink / raw)
To: Lin Zhang; +Cc: davem, linux-kernel, netdev
On Thu, 2017-07-06 at 02:16 -0700, Eric Dumazet wrote:
> On Thu, 2017-07-06 at 17:01 +0800, Lin Zhang wrote:
> > In the pull_pages code block, if the first frags size > eat,
> > we can end the loop in advance to avoid extra copy.
> >
> > Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
> > ---
> > net/core/skbuff.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index f990eb8..c00a1df 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -1720,6 +1720,10 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta)
> > skb_shinfo(skb)->frags[k].page_offset += eat;
> > skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
> > eat = 0;
> > + if (!i) {
> > + k = skb_shinfo(skb)->nr_frags;
> > + break;
> > + }
> > }
> > k++;
> > }
>
> 1) net-next is closed during merge window.
>
> 2) This change is completely buggy.
> How have you tested it exactly ???
Hmm... it looks like I was wrong, but 1) still applies ;)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail()
2017-07-06 9:23 ` Eric Dumazet
@ 2017-07-06 9:35 ` lin zhang
2017-07-06 9:48 ` Eric Dumazet
0 siblings, 1 reply; 5+ messages in thread
From: lin zhang @ 2017-07-06 9:35 UTC (permalink / raw)
To: Eric Dumazet; +Cc: David Miller, linux-kernel, netdev
2017-07-06 17:23 GMT+08:00 Eric Dumazet <eric.dumazet@gmail.com>:
> On Thu, 2017-07-06 at 02:16 -0700, Eric Dumazet wrote:
>> On Thu, 2017-07-06 at 17:01 +0800, Lin Zhang wrote:
>> > In the pull_pages code block, if the first frags size > eat,
>> > we can end the loop in advance to avoid extra copy.
>> >
>> > Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
>> > ---
>> > net/core/skbuff.c | 4 ++++
>> > 1 file changed, 4 insertions(+)
>> >
>> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>> > index f990eb8..c00a1df 100644
>> > --- a/net/core/skbuff.c
>> > +++ b/net/core/skbuff.c
>> > @@ -1720,6 +1720,10 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta)
>> > skb_shinfo(skb)->frags[k].page_offset += eat;
>> > skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
>> > eat = 0;
>> > + if (!i) {
>> > + k = skb_shinfo(skb)->nr_frags;
>> > + break;
>> > + }
>> > }
>> > k++;
>> > }
>>
>> 1) net-next is closed during merge window.
>>
>> 2) This change is completely buggy.
>> How have you tested it exactly ???
>
> Hmm... it looks like I was wrong, but 1) still applies ;)
>
>
>
>
thanks, i am a newer, "net-next is closed" it means i need repost it
after net-next reopened?
regards
--
Lin Zhang
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail()
2017-07-06 9:35 ` lin zhang
@ 2017-07-06 9:48 ` Eric Dumazet
0 siblings, 0 replies; 5+ messages in thread
From: Eric Dumazet @ 2017-07-06 9:48 UTC (permalink / raw)
To: lin zhang; +Cc: David Miller, linux-kernel, netdev
On Thu, 2017-07-06 at 17:35 +0800, lin zhang wrote:
> thanks, i am a newer, "net-next is closed" it means i need repost it
> after net-next reopened?
Yes, please read Documentation/networking/netdev-FAQ.txt for details.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-07-06 9:48 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2017-07-06 9:01 [PATCH net-next] skbuff: optimize the pull_pages code in __pskb_pull_tail() Lin Zhang
2017-07-06 9:16 ` Eric Dumazet
2017-07-06 9:23 ` Eric Dumazet
2017-07-06 9:35 ` lin zhang
2017-07-06 9:48 ` Eric Dumazet
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