Bug 138067

Summary:	kernel/network device/ txqueuelen / no errors
Product:	Gentoo Linux	Reporter:	Denys <nuclearcat>
Component:	[OLD] Core system	Assignee:	Gentoo Kernel Bug Wranglers and Kernel Maintainers <kernel>
Status:	RESOLVED UPSTREAM
Severity:	normal
Priority:	High
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Denys 2006-06-26 09:03:09 UTC

I have loaded PC with e100 network cards. Since load reached 50Mbit/s + compression software, PC was not able to handle the load (because of weak CPU i think). I start digging the problem, and after i turn 
ethtool -s eth1 msglvl 256
i so message in dmesg
[4296026.422000] e100: eth1: e100_xmit_frame: No space for CB
In the same time there is no errors, dropped packets or etc on eth1
But actually, packets forwarded from tun(tap) device dropped, and that drops is not shown in any statistic.
I did "ip link set eth1 txqueuelen 10000"
and problems is solved.

I have looked in e100 driver:
case -ENOSPC:
/* We queued the skb, but now we're out of space. */
DPRINTK(TX_ERR, DEBUG, "No space for CB\n");
netif_stop_queue(netdev);
break;

Seems it is hitting this rule. 
My question, is any person can suggest in kernel maillist to show packets dropped by ENOSPC in ifconfig or netstat -s ?

Comment 1 Denys 2006-06-26 09:10:31 UTC

I forgot to mention
today i did emerge of latest kernel 2.6.16-gentoo-r9

Comment 2 Denys 2006-06-26 09:11:30 UTC

I forgot to mention
today i did emerge of latest kernel 2.6.16-gentoo-r9

Comment 3 Daniel Drake (RETIRED) gentoo-dev

2006-06-27 05:20:25 UTC

This question belongs on the linux netdev mailing list.