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

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Message-ID: <47A07FEA.3000702@trash.net>
Date:	Wed, 30 Jan 2008 14:47:22 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	Jeff Chua <jeff.chua.linux@...il.com>
CC:	Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu>,
	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

Jeff Chua wrote:
> On Jan 29, 2008 6:53 PM, Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu> wrote:
> 
>> As the problem can be reproduced so easily, could you capture a full TCP
>> session and send the pcap file? Thus it could be analyzed, replayed, etc.
>> and found the reason why the patch above slows down the printing.
>> By reverting back it we loose TCP reopening support.
> 
> Not an expert here. I use 'tcpdump -i lo' and don't see anything
> different between the good and bad.  Anyway, attached are the good and
> bad log files.
> 
> There's a slight pause of 27 seconds after 502 jobs (both good and bad
> runs), then the good one will resume and transmit in burst until
> completing all the 1000 times. The bad run will resume and transmit
> one-by-one every 3 seconds.
> 
> Please tell me what options to use with tcpdump to dump more useful output.


A binary dump would be more useful:

tcpdump -i lo -w <outfile>

and I guess Jozsef also wants "-s 0" so the full packets are included.
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