Re: Bug, kernel panic, NULL dereference , cleanup_once / icmp_route_lookup.clone.19.clone / nat , 2.6.39-rc7-git11

Denys Fedoryshchenko
2011-05-19T06:11:03Z

On Thu, 19 May 2011 07:19:57 +0200, Eric Dumazet wrote:
> Le mercredi 18 mai 2011 à 21:29 +0200, Eric Dumazet a écrit :
>> Le mercredi 18 mai 2011 à 17:52 +0200, Eric Dumazet a écrit :
>>
>> > Hmm, it seems we have some inetpeer refcount leak somewhere.
>> >
>> > Maybe one (struct rtable)->peer is not released on dst/rtable
>> removal,
>> > or we also leak dst/rtable (and their ->peer inetpeer)
>> >
>> > Watch :
>> >
>> > grep peer /proc/slabinfo
>> > grep dst /proc/slabinfo
>> >
>>
>> FYI, I started a bisection to find the faulty commit.
>>
>
> Oh well, of course this came to 2c8cec5c10bced240
> (ipv4: Cache learned PMTU information in inetpeer.)
>
> So my method to check if we have a leak might be wrong, since the
> above
> commit let cache full of garbage, and hope that following lookups
> will
> find and evict obsolete dst.
>
> Thats getting difficult :(
>
> Could you please send us
>
> grep . /proc/sys/net/ipv4/route/*
>
> Thanks !
NewNet-PPPoE ~ # grep . /proc/sys/net/ipv4/route/*
/proc/sys/net/ipv4/route/error_burst:5000
/proc/sys/net/ipv4/route/error_cost:1000
grep: /proc/sys/net/ipv4/route/flush: Permission denied
/proc/sys/net/ipv4/route/gc_elasticity:8
/proc/sys/net/ipv4/route/gc_interval:60
/proc/sys/net/ipv4/route/gc_min_interval:0
/proc/sys/net/ipv4/route/gc_min_interval_ms:500
/proc/sys/net/ipv4/route/gc_thresh:32768
/proc/sys/net/ipv4/route/gc_timeout:300
/proc/sys/net/ipv4/route/max_size:524288
/proc/sys/net/ipv4/route/min_adv_mss:256
/proc/sys/net/ipv4/route/min_pmtu:552
/proc/sys/net/ipv4/route/mtu_expires:600
/proc/sys/net/ipv4/route/redirect_load:20
/proc/sys/net/ipv4/route/redirect_number:9
/proc/sys/net/ipv4/route/redirect_silence:20480

I think it is default one.

PMTU is very actual for that, as it is pppoe, and up to 2k interfaces
terminated there.

I don't know, if it matters, but
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS
--clamp-mss-to-pmtu
also there.

I can generate and put "ip route ls cache" and any other info.