[-next] Regression: ssh log in slowdown

Thanks, I applied the series "[PATCH 0/4] Checksum fixes", and the fix
above, but it doesn't help.

Note that I'm also using NFS root, which doesn't seem to be affected.
I can happily run "ls -R /" on the serial console during the 10 s delay 

in ssh.

Geert,

Thanks for your patience!

Can you try one more patch below with the series applied? Also, can you 
look at 'netstat -s' to see if UDP checksum errors are being reported.

Thanks,
Tom 

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index fdb510c..4b722bc 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h

@@ -2820,8 +2820,8 @@ static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
 	if (complete || skb->len <= CHECKSUM_BREAK) {
 		__sum16 csum;
 
+		/* skb->csum valid set in __skb_checksum_complete */
 		csum = __skb_checksum_complete(skb);
-		skb->csum_valid = !csum;
 		return csum;
 	}
 

diff --git a/net/core/datagram.c b/net/core/datagram.c
index cf6cc4e..488dd1a 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c

@@ -744,6 +744,7 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len)
 		    !skb->csum_complete_sw)
 			netdev_rx_csum_fault(skb->dev);
 	}
+	skb->csum_valid = !sum;
 	return sum;
 }
 EXPORT_SYMBOL(__skb_checksum_complete_head);

@@ -767,6 +768,7 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb)
 	skb->csum = csum;
 	skb->ip_summed = CHECKSUM_COMPLETE;
 	skb->csum_complete_sw = 1;
+	skb->csum_valid = !sum;
 
 	return sum;
 }

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bf92824..9cd5344 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c

@@ -689,6 +689,9 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 	new->ooo_okay		= old->ooo_okay;
 	new->no_fcs		= old->no_fcs;
 	new->encapsulation	= old->encapsulation;
+	new->encap_hdr_csum	= old->encap_hdr_csum;
+	new->csum_valid		= old->csum_valid;
+	new->csum_complete_sw	= old->csum_complete_sw;
 #ifdef CONFIG_XFRM
 	new->sp			= secpath_get(old->sp);
 #endif

Hi Tom,

On Fri, Jun 13, 2014 at 5:37 PM, Tom Herbert [off-list ref] wrote:

quoted

Thanks, I applied the series "[PATCH 0/4] Checksum fixes", and the fix
above, but it doesn't help.

Note that I'm also using NFS root, which doesn't seem to be affected.
I can happily run "ls -R /" on the serial console during the 10 s delay

in ssh.

Can you try one more patch below with the series applied? Also, can you

This patch fixes the issue. Thanks!

look at 'netstat -s' to see if UDP checksum errors are being reported.

Indeed, errors are reported under Udp/InCsumErrors.
With this new patch, no errors are reported.

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds