Re: owner-Match in 2.6.20-rc5 (fwd)

Re: owner-Match in 2.6.20-rc5 (fwd)

[David Miller]

From: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Date: Thu, 25 Jan 2007 21:31:56 +0100 (CET)

> The report below was posted on the netfilter user list. Isn't there any 
> ill side effect by reverting the change?

Performance regression :-(

This optimization saves a whole handful of heavy atomic operations in
the packet transmit path of TCP.

As I understand it, the owner-Match is not in the upstream tree, and
it's the only thing that cares, so I see no reason to cater for it.

Re: owner-Match in 2.6.20-rc5 (fwd)

[Jan Engelhardt]

>> The report below was posted on the netfilter user list. Isn't there any 
>> ill side effect by reverting the change?
>
>Performance regression :-(
>
>This optimization saves a whole handful of heavy atomic operations in
>the packet transmit path of TCP.
>
>As I understand it, the owner-Match is not in the upstream tree, and
>it's the only thing that cares, so I see no reason to cater for it.

For me, it's there.
-rw-r--r-- 1 jengelh users 2247 Jan 25 21:37
/erk/kernel/linux-2.6.20-rc6/net/ipv4/netfilter/ipt_owner.c


	-`J'
-- 

Re: owner-Match in 2.6.20-rc5 (fwd)

[David Miller]

From: Jan Engelhardt <jengelh@linux01.gwdg.de>
Date: Thu, 25 Jan 2007 22:07:07 +0100 (MET)

> 
> >> The report below was posted on the netfilter user list. Isn't there any 
> >> ill side effect by reverting the change?
> >
> >Performance regression :-(
> >
> >This optimization saves a whole handful of heavy atomic operations in
> >the packet transmit path of TCP.
> >
> >As I understand it, the owner-Match is not in the upstream tree, and
> >it's the only thing that cares, so I see no reason to cater for it.
> 
> For me, it's there.
> -rw-r--r-- 1 jengelh users 2247 Jan 25 21:37
> /erk/kernel/linux-2.6.20-rc6/net/ipv4/netfilter/ipt_owner.c

Ok, I'll see what I can do about this :-)

Re: owner-Match in 2.6.20-rc5 (fwd)

[Jan Engelhardt]

>> >> The report below was posted on the netfilter user list. Isn't there any 
>> >> ill side effect by reverting the change?
>> >
>> >Performance regression :-(
>> >
>> >This optimization saves a whole handful of heavy atomic operations in
>> >the packet transmit path of TCP.
>> >
>> >As I understand it, the owner-Match is not in the upstream tree, and
>> >it's the only thing that cares, so I see no reason to cater for it.
>> 
>> For me, it's there.
>> -rw-r--r-- 1 jengelh users 2247 Jan 25 21:37
>> /erk/kernel/linux-2.6.20-rc6/net/ipv4/netfilter/ipt_owner.c
>
>Ok, I'll see what I can do about this :-)
>

People really depend on this. Much more than than pid/comm/smpunsafe stuff.
For example, a web server [cgi enabled, etc.] which also runs squid,
to force all webtraffic through it:

-A OUTPUT -p tcp --dport 80 -m owner ! --uid-owner
  squid -j REDIRECT --to-ports 3128


	-`J'
-- 

Re: owner-Match in 2.6.20-rc5 (fwd)

[David Miller]

From: Jan Engelhardt <jengelh@linux01.gwdg.de>
Date: Thu, 25 Jan 2007 23:14:49 +0100 (MET)

> People really depend on this. Much more than than pid/comm/smpunsafe stuff.
> For example, a web server [cgi enabled, etc.] which also runs squid,
> to force all webtraffic through it:
> 
> -A OUTPUT -p tcp --dport 80 -m owner ! --uid-owner
>   squid -j REDIRECT --to-ports 3128

FWIW I've simply reverted the change in question to fix this.
Will push to Linus soon.