Dear Friends,

I have been receiving regular Kernel Panic (almost every second day) as under on My CentOS release 4.4 (Final) Kernel Version 2.6.9-42.EL. The error is received after "HTB init, kernel part version 3.17", but its NOT always EVERY "HTB init, kernel part version 3.17" message in the /var/log/messages log.

Here is the message log :

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Feb 2 14:45:21 localhost kernel: HTB init, kernel part version 3.17
Feb 2 14:45:21 localhost kernel: Unable to handle kernel paging request at virtual address 00100100
Feb 2 14:45:21 localhost kernel: printing eip:
Feb 2 14:45:21 localhost kernel: c02cd207
Feb 2 14:45:21 localhost kernel: *pde = 00000000
Feb 2 14:45:21 localhost kernel: Oops: 0000 [#1]
Feb 2 14:45:21 localhost kernel: Modules linked in: ipt_MARK iptable_mangle ipt_LOG ipt_limit ipt_state iptable_filter ipt_MASQUERADE ipt_REDIRECT iptable_nat ip_conntrack ip_tables cls_fw sch_sfq cls_u32 sch_htb md5 ipv6 ppp_synctty ppp_async crc_ccitt ppp_generic slhc dm_mirror dm_mod button battery ac uhci_hcd ehci_hcd 8139too mii floppy ext3 jbd
Feb 2 14:45:21 localhost kernel: CPU: 0
Feb 2 14:45:21 localhost kernel: EIP: 0060:[<c02cd207>] Not tainted VLI
Feb 2 14:45:21 localhost kernel: EFLAGS: 00010286 (2.6.9-42.EL)
Feb 2 14:45:21 localhost kernel: EIP is at qdisc_lookup+0x31/0x47
Feb 2 14:45:21 localhost kernel: eax: 001000b8 ebx: f7f4a080 ecx: 001000b8 edx: 00100100
Feb 2 14:45:21 localhost kernel: esi: 00010000 edi: 00010001 ebp: f7f4a080 esp: f37b1c98
Feb 2 14:45:21 localhost kernel: ds: 007b es: 007b ss: 0068
Feb 2 14:45:21 localhost kernel: Process tc (pid: 19206, threadinfo=f37b1000 task=f46b6800)
Feb 2 14:45:21 localhost kernel: Stack: 00010000 00010000 c02ce466 00000000 00000000 f7ff3dc0 f3add000 f3fd8280
Feb 2 14:45:21 localhost kernel: 00000246 f3fd8280 c038d160 c02ce3bc 00000018 c02c4e97 0000003c 00000006
Feb 2 14:45:21 localhost kernel: 00000868 f3add000 f7fe6c80 f3fd8280 f7fe6c80 f3fd8280 00000868 f7fecb80
Feb 2 14:45:21 localhost kernel: Call Trace:
Feb 2 14:45:21 localhost kernel: [<c02ce466>] tc_ctl_tclass+0xaa/0x1e4
Feb 2 14:45:21 localhost kernel: [<c02ce3bc>] tc_ctl_tclass+0x0/0x1e4
Feb 2 14:45:21 localhost kernel: [<c02c4e97>] rtnetlink_rcv+0x225/0x317
Feb 2 14:45:21 localhost kernel: [<c02d14c5>] netlink_data_ready+0x14/0x43
Feb 2 14:45:21 localhost kernel: [<c02d0c29>] netlink_sendskb+0x52/0x6b
Feb 2 14:45:21 localhost kernel: [<c02d12e1>] netlink_sendmsg+0x269/0x278
Feb 2 14:45:21 localhost kernel: [<c02b35fb>] sock_sendmsg+0xdb/0xf7
Feb 2 14:45:21 localhost kernel: [<c0121853>] autoremove_wake_function+0x0/0x2d
Feb 2 14:45:21 localhost kernel: [<c02b8ffe>] verify_iovec+0x76/0xc2
Feb 2 14:45:21 localhost kernel: [<c02b4d8c>] sys_sendmsg+0x1ee/0x23b
Feb 2 14:45:21 localhost kernel: [<c015c001>] handle_mm_fault+0xec/0x212
Feb 2 14:45:21 localhost kernel: [<c02b4aad>] sys_setsockopt+0x5c/0x89
Feb 2 14:45:21 localhost kernel: [<c02b4ad1>] sys_setsockopt+0x80/0x89
Feb 2 14:45:21 localhost kernel: [<c02b5193>] sys_socketcall+0x1df/0x1fb
Feb 2 14:45:21 localhost kernel: [<c0318d93>] syscall_call+0x7/0xb
Feb 2 14:45:21 localhost kernel: Code: 8b 80 2c 01 00 00 8d 48 b8 8b 51 48 0f 18 02 90 8d 93 2c 01 00 00 39 d0 74 22 39 71 14 75 04 89 c8 eb 1b 8b 51 48 8d 42 b8 89 c1 <8b> 40 48 0f 18 00 90 8d 83 2c 01 00 00 39 c2 eb dc 31 c0 5b 5e
Feb 2 14:45:21 localhost kernel: <0>Fatal exception: panic in 5 seconds
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Here is a sample of our tc.sh script :

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#!/bin/bash

QOS=/sbin/tc
IFCONFIG=/sbin/ifconfig

$QOS qdisc del dev eth0 root
$IFCONFIG eth0 txqueuelen 32
$QOS qdisc add dev eth0 root handle 1:0 htb default 998
$QOS class add dev eth0 parent 1:0 classid 1:1 htb rate 2048kbit burst 64k cburst 64k
$QOS class add dev eth0 parent 1:1 classid 1:999 htb rate 2048kbit ceil 2048kbit quantum 12187 burst 2048kbit cburst 2048kbit prio 1
$QOS filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip tos 0x10 0xff flowid 1:999
$QOS filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip protocol 1 0xff flowid 1:999
$QOS qdisc add dev eth0 parent 1:999 sfq perturb 16 quantum 12187
$QOS class add dev eth0 parent 1:1 classid 1:998 htb rate 64kbit ceil 128kbit quantum 5062 burst 128kbit cburst 128kbit prio 3
$QOS qdisc add dev eth0 parent 1:998 sfq perturb 16 quantum 5062
$QOS class add dev eth0 parent 1:1 classid 1:15 htb rate 256kbit ceil 512kbit quantum 8625 burst 512kbit cburst 512kbit prio 2
$QOS filter add dev eth0 parent 1:0 protocol ip prio 2 handle 5 fw classid 1:15
$QOS qdisc add dev eth0 parent 1:15 sfq perturb 16 quantum 8625
$QOS class add dev eth0 parent 1:1 classid 1:16 htb rate 32kbit ceil 64kbit quantum 5062 burst 64kbit cburst 64kbit prio 3
$QOS filter add dev eth0 parent 1:0 protocol ip prio 3 handle 6 fw classid 1:16
$QOS qdisc add dev eth0 parent 1:16 sfq perturb 16 quantum 5062
$QOS class add dev eth0 parent 1:1 classid 1:17 htb rate 64kbit ceil 128kbit quantum 5062 burst 128kbit cburst 128kbit prio 3
$QOS filter add dev eth0 parent 1:0 protocol ip prio 3 handle 7 fw classid 1:17
$QOS qdisc add dev eth0 parent 1:17 sfq perturb 16 quantum 5062
$QOS class add dev eth0 parent 1:1 classid 1:18 htb rate 64kbit ceil 64kbit quantum 8625 burst 64kbit cburst 64kbit prio 2
$QOS filter add dev eth0 parent 1:0 protocol ip prio 2 handle 8 fw classid 1:18
$QOS qdisc add dev eth0 parent 1:18 sfq perturb 16 quantum 8625
..........
..........

$QOS qdisc del dev eth1 root
$IFCONFIG eth1 txqueuelen 32
$QOS qdisc add dev eth1 root handle 2:0 htb default 998
$QOS class add dev eth1 parent 2:0 classid 2:1 htb rate 2048kbit burst 64k cburst 64k
$QOS class add dev eth1 parent 2:1 classid 2:999 htb rate 2048kbit ceil 2048kbit quantum 12187 burst 2048kbit cburst 2048kbit prio 1
$QOS filter add dev eth1 parent 2:0 protocol ip prio 1 u32 match ip tos 0x10 0xff flowid 2:999
$QOS filter add dev eth1 parent 2:0 protocol ip prio 1 u32 match ip protocol 1 0xff flowid 2:999
$QOS qdisc add dev eth1 parent 2:999 sfq perturb 16 quantum 12187
$QOS class add dev eth1 parent 2:1 classid 2:998 htb rate 64kbit ceil 128kbit quantum 5062 burst 128kbit cburst 128kbit prio 3
$QOS qdisc add dev eth1 parent 2:998 sfq perturb 16 quantum 5062
$QOS class add dev eth1 parent 2:1 classid 2:15 htb rate 256kbit ceil 512kbit quantum 8625 burst 512kbit cburst 512kbit prio 2
$QOS filter add dev eth1 parent 2:0 protocol ip prio 2 handle 5 fw classid 2:15
$QOS qdisc add dev eth1 parent 2:15 sfq perturb 16 quantum 8625
$QOS class add dev eth1 parent 2:1 classid 2:16 htb rate 32kbit ceil 64kbit quantum 5062 burst 64kbit cburst 64kbit prio 3
$QOS filter add dev eth1 parent 2:0 protocol ip prio 3 handle 6 fw classid 2:16
$QOS qdisc add dev eth1 parent 2:16 sfq perturb 16 quantum 5062
$QOS class add dev eth1 parent 2:1 classid 2:17 htb rate 64kbit ceil 128kbit quantum 5062 burst 128kbit cburst 128kbit prio 3
$QOS filter add dev eth1 parent 2:0 protocol ip prio 3 handle 7 fw classid 2:17
$QOS qdisc add dev eth1 parent 2:17 sfq perturb 16 quantum 5062
$QOS class add dev eth1 parent 2:1 classid 2:18 htb rate 64kbit ceil 64kbit quantum 8625 burst 64kbit cburst 64kbit prio 2
$QOS filter add dev eth1 parent 2:0 protocol ip prio 2 handle 8 fw classid 2:18
$QOS qdisc add dev eth1 parent 2:18 sfq perturb 16 quantum 8625
..........
..........
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Can you please advise what's going on ? If this is related to kernel version, please advise what kernel to install or should I install recompiled kernel (with what options enabled ? I am doing NAT, MASQ, IPROUTE along with TC) from source on my development platform.

A early reply will be appreciated.

Thanks and regards,
Rashpal Singh