Re: cups slow on linux-2.6.24

["Jeff Chua" <jeff.chua.linux@gmail.com>]

On Feb 2, 2008 10:44 PM, Jozsef Kadlecsik <kadlec@blackhole.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.