[cups.bugs] cups slow on linux-2.6.24

Patrick McHardy kaber at trash.net
Wed Jan 30 10:23:53 PST 2008

Jeff Chua wrote:
> On Jan 29, 2008 6:53 PM, Jozsef Kadlecsik <kadlec at blackhole.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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