* [PATCH] net/udp_offload: Drop unnecessary continue
@ 2014-08-13 9:16 Himangi Saraogi
2014-08-13 14:48 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Himangi Saraogi @ 2014-08-13 9:16 UTC (permalink / raw)
To: David S. Miller, Alexey Kuznetsov, James Morris,
Hideaki YOSHIFUJI, Patrick McHardy, netdev, linux-kernel
Cc: Julia Lawall
Continue is not needed at the bottom of a loop.
The Coccinelle semantic patch implementing this change is:
@@
@@
for (...;...;...) {
...
if (...) {
...
- continue;
}
}
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
---
net/ipv4/udp_offload.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 59035bc..62d5b9b 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -269,10 +269,8 @@ unflush:
continue;
uh2 = (struct udphdr *)(p->data + off);
- if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
+ if ((*(u32 *)&uh->source != *(u32 *)&uh2->source))
NAPI_GRO_CB(p)->same_flow = 0;
- continue;
- }
}
skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] net/udp_offload: Drop unnecessary continue
2014-08-13 9:16 [PATCH] net/udp_offload: Drop unnecessary continue Himangi Saraogi
@ 2014-08-13 14:48 ` Eric Dumazet
2014-08-13 17:06 ` Alexei Starovoitov
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2014-08-13 14:48 UTC (permalink / raw)
To: Himangi Saraogi
Cc: David S. Miller, Alexey Kuznetsov, James Morris,
Hideaki YOSHIFUJI, Patrick McHardy, netdev, linux-kernel,
Julia Lawall
On Wed, 2014-08-13 at 14:46 +0530, Himangi Saraogi wrote:
> Continue is not needed at the bottom of a loop.
>
> The Coccinelle semantic patch implementing this change is:
>
> @@
> @@
>
> for (...;...;...) {
> ...
> if (...) {
> ...
> - continue;
> }
> }
>
> Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
> Acked-by: Julia Lawall <julia.lawall@lip6.fr>
> ---
> net/ipv4/udp_offload.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> index 59035bc..62d5b9b 100644
> --- a/net/ipv4/udp_offload.c
> +++ b/net/ipv4/udp_offload.c
> @@ -269,10 +269,8 @@ unflush:
> continue;
>
> uh2 = (struct udphdr *)(p->data + off);
> - if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
> + if ((*(u32 *)&uh->source != *(u32 *)&uh2->source))
> NAPI_GRO_CB(p)->same_flow = 0;
> - continue;
> - }
> }
>
> skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
Please do not do that.
If we add another check later, we'll miss that the 'continue;' needs to
be put back.
GRO stack is quite difficult to maintain, I prefer we keep this as is
for consistency and code readability.
Every time we clear same_flow, we use the "continue;" construct.
if (...) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
<here we can eventually add some other check>
Compiler generates the same code anyway.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] net/udp_offload: Drop unnecessary continue
2014-08-13 14:48 ` Eric Dumazet
@ 2014-08-13 17:06 ` Alexei Starovoitov
0 siblings, 0 replies; 3+ messages in thread
From: Alexei Starovoitov @ 2014-08-13 17:06 UTC (permalink / raw)
To: Eric Dumazet
Cc: Himangi Saraogi, David S. Miller, Alexey Kuznetsov, James Morris,
Hideaki YOSHIFUJI, Patrick McHardy, netdev, linux-kernel,
Julia Lawall
On Wed, Aug 13, 2014 at 07:48:11AM -0700, Eric Dumazet wrote:
> On Wed, 2014-08-13 at 14:46 +0530, Himangi Saraogi wrote:
> > Continue is not needed at the bottom of a loop.
> >
> > The Coccinelle semantic patch implementing this change is:
> >
> > @@
> > @@
> >
> > for (...;...;...) {
> > ...
> > if (...) {
> > ...
> > - continue;
> > }
> > }
> >
> > Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
> > Acked-by: Julia Lawall <julia.lawall@lip6.fr>
> > ---
> > net/ipv4/udp_offload.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> > index 59035bc..62d5b9b 100644
> > --- a/net/ipv4/udp_offload.c
> > +++ b/net/ipv4/udp_offload.c
> > @@ -269,10 +269,8 @@ unflush:
> > continue;
> >
> > uh2 = (struct udphdr *)(p->data + off);
> > - if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
> > + if ((*(u32 *)&uh->source != *(u32 *)&uh2->source))
> > NAPI_GRO_CB(p)->same_flow = 0;
> > - continue;
> > - }
> > }
> >
> > skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
>
>
> Please do not do that.
>
> If we add another check later, we'll miss that the 'continue;' needs to
> be put back.
>
> GRO stack is quite difficult to maintain, I prefer we keep this as is
> for consistency and code readability.
+1
this code as-is is definitely more readable
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-08-13 9:16 [PATCH] net/udp_offload: Drop unnecessary continue Himangi Saraogi
2014-08-13 14:48 ` Eric Dumazet
2014-08-13 17:06 ` Alexei Starovoitov
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