linux-kernel - Re: cups slow on linux-2.6.24

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Message-ID: <b6a2187b0802030808v5ca48d96t697c5f3a1c638ded@mail.gmail.com>
Date:	Mon, 4 Feb 2008 00:08:28 +0800
From:	"Jeff Chua" <jeff.chua.linux@...il.com>
To:	"Jozsef Kadlecsik" <kadlec@...ckhole.kfki.hu>
Cc:	"Patrick McHardy" <kaber@...sh.net>,
	lkml <linux-kernel@...r.kernel.org>,
	"Krzysztof Piotr Oledzki" <ole@....pl>,
	"David S. Miller" <davem@...emloft.net>,
	cups-bugs <cups-bugs@...ysw.com>,
	"Netfilter Development Mailinglist" <netfilter-devel@...r.kernel.org>
Subject: Re: cups slow on linux-2.6.24

On Feb 2, 2008 10:44 PM, Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu> wrote:

> Could I ask you to make two another tests? (I have been unable to
> reproduce the bug so far, but it must be my fault.)

You need to send more than 510 jobs to see the problem.

> In both cases enable loggin invalid messages as Patrick wrote in a previous mail:
> # modprobe ipt_LOG
> # echo 255 >/proc/sys/net/netfilter/nf_conntrack_log_invalid

Ok.

> In the first case run the unpatched 2.4.24 kernel and before doing
> any printing, start dumping all the traffic at the 515 port so that we
> won't miss any connection and send the dump file:
> # tcpdump -i lo -s 0 -w dump.pcap tcp port 515

Attached are the file dump1.bad, and dmesg.bad.

The console only starts printing out the "nf_ct_tcp: invalid packed
ignored" messages after the 22 seconds "pause". Look for pause at
"23:40:27.454677", and resume at "23:40:59.469704". The first console
message at "23:40:59".

> In the second case run the patched kernel and just start printing: do you
> get any 'nf_ct_tcp: invalid SYN' kernel message?

No such message. Even after trying many times. But there's still a 26
"pause" from "23:49:41.368812" to "23:50:07.392278". It's able to
resume and continue printing in "burst".

These tests were ran with just 520 jobs using:

for((i=1; i<520;i++)); do echo $i | lpr -Plp; done

Sorry for the delay. Traveling.

Thanks,
Jeff.
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