Thread (9 messages) flat view 9 messages, 3 authors, 2017-06-26

Re: DNS (?) not working on G5 (64-bit powerpc) (was [net-next,v3,3/3] udp: try to avoid 2 cache miss on dequeue)

From: Paolo Abeni <pabeni@redhat.com>
Date: 2017-06-23 11:59:46
Also in: netdev

On Fri, 2017-06-23 at 16:59 +1000, Michael Ellerman wrote:
Hannes Frederic Sowa [off-list ref] writes:
quoted
On Thu, Jun 22, 2017, at 22:57, Paolo Abeni wrote:
quoted
Can you please check if the following patch fixes the issue? Only
compiled tested here.

Thanks!!!
---
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 067a607..80d89fe 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1446,16 +1446,19 @@ static struct sk_buff
*__first_packet_length(struct sock *sk,
 {
 	struct sk_buff *skb;
 
-       while ((skb = skb_peek(rcvq)) != NULL &&
-              udp_lib_checksum_complete(skb)) {
-               __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
-                               IS_UDPLITE(sk));
-               __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
-                               IS_UDPLITE(sk));
-               atomic_inc(&sk->sk_drops);
-               __skb_unlink(skb, rcvq);
-               *total += skb->truesize;
-               kfree_skb(skb);
+       while ((skb = skb_peek(rcvq)) != NULL) {
+               if (udp_lib_checksum_complete(skb)) {
+                       __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
+                                       IS_UDPLITE(sk));
+                       __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
+                                       IS_UDPLITE(sk));
+                       atomic_inc(&sk->sk_drops);
+                       __skb_unlink(skb, rcvq);
+                       *total += skb->truesize;
+                       kfree_skb(skb);
+               } else {
+                       udp_set_dev_scratch(skb);
It needs a "break;" here.
quoted
+               }
 	}
 	return skb;
 }
That works!

$ wget google.com
--2017-06-23 16:56:31--  http://google.com/
Resolving proxy.pmdw.com (proxy.pmdw.com)... 10.1.2.3
Connecting to proxy.pmdw.com (proxy.pmdw.com)|10.1.2.3|:3128... connected.
Proxy request sent, awaiting response... 302 Found
Location: http://www.google.com.au/?gfe_rd=cr&ei=n7tMWeb9JYPr8wfg4LXYAQ [following]
--2017-06-23 16:56:31--  http://www.google.com.au/?gfe_rd=cr&ei=n7tMWeb9JYPr8wfg4LXYAQ
Reusing existing connection to proxy.pmdw.com:3128.
Proxy request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Saving to: ‘index.html’


The patch had whitespace issues or something and I had to apply it by
hand, here's what I actually tested.
Thank you!

I'll submit formally the patch after some more testing.

I noticed this version has entered the ppc patchwork, but I think that
the formal submission should go towards the net-next tree.

Cheers,

Paolo
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