Re: PROBLEM: NAT over 3c59x cards freezes interactivity on 2.6.2

From: Chad Walstrom
Date: Fri Feb 20 2004 - 17:51:18 EST


On Thu, Feb 12, 2004 at 06:42:08PM -0800, Andrew Morton wrote:
> Chad Walstrom <chewie@xxxxxxxxxxxx> wrote:
> >
> > [2.] DETAILS: Upon upgrading from 2.4.x to 2.6.2, I've noticed that my
> > workstation/NAT box freezes on interactive processes while transfering
> > large files over NAT to other machines on the network.
>
> Please monitor the system time with top or `vmstat 1'. Is it excessive?

I'm not sure what excessive might mean. There doesn't seem to be any
spikes in memory consumption. Following is the output from 'vmstat 1'.
The number of procs waiting for run time increases when the
interactivity freezes (while the laptop is downloading files over the
workstation's NAT). The '6' and '5' both occur during download attempts
and interactivy freezes. When I kill the download, interactivy resumes,
and the waiting processes drops.

Script started on Fri Feb 20 16:17:30 2004
[16:17:30] chewie@skuld (501)$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
2 0 9364 2560 46256 300188 0 0 10 12 35 44 96 1 3 0
1 0 9364 2560 46256 300188 0 0 0 0 1008 63 100 0 0 0
1 0 9364 2560 46264 300188 0 0 0 12 1008 56 100 0 0 0
1 0 9364 2368 46264 300216 0 0 0 0 1151 173 96 4 0 0
1 0 9364 2240 46272 300340 0 0 0 12 1690 654 93 7 0 0
6 1 9364 3584 45232 300448 0 0 0 8 1600 737 92 8 0 0
3 0 9364 3584 45236 300600 0 0 0 1 1834 846 90 10 0 0
3 0 9364 3528 45236 300656 0 0 0 0 1308 350 98 2 0 0
3 0 9364 3528 45240 300664 0 0 0 12 1055 113 99 1 0 0
1 0 9364 3144 45240 300848 0 0 0 0 1898 913 92 8 0 0
1 0 9364 2888 45240 301088 0 0 0 0 2172 1249 85 15 0 0
1 0 9364 2696 45240 301304 0 0 0 0 2107 1148 87 13 0 0
5 0 9364 2696 45244 301472 0 0 0 12 1554 864 86 14 0 0
1 0 9364 2504 45244 301508 0 0 0 0 473 165 95 5 0 0
1 0 9364 2568 45244 301584 0 0 0 0 1289 438 100 0 0 0
1 0 9364 2568 45244 301592 0 0 0 0 1039 91 99 1 0 0
1 0 9364 2568 45304 301592 0 0 0 112 1023 83 100 0 0 0
1 0 9364 2568 45304 301596 0 0 0 0 1016 100 100 0 0 0

[16:17:49] chewie@skuld (502)$ exit
exit

Script done on Fri Feb 20 16:17:54 2004

> A kernel profile might tell us what is going on. See
> Documentation/basic_profiling.txt.

I'll have to recompile the kernel to test this for you. I'll do so and
compile 2.6.3.

> If you remove all the netfilter rules, what happens?

Then I wouldn't be able to NAT. ;-) The workstation works fine as a
standalone. I've downloaded large files w/o too much difficulty, and
interactivity remains stable. The only time I see problems is when I'm
downloading files through NAT to the laptop.

(Sorry it took so long to reply. We're a bit down in the weather at our
house lately.)

--
Chad Walstrom <chewie@xxxxxxxxxxxx> http://www.wookimus.net/
assert(expired(knowledge)); /* core dump */

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