Re: 2.6.14-mm1

From: Valdis . Kletnieks
Date: Mon Nov 07 2005 - 15:22:22 EST


On Mon, 07 Nov 2005 11:52:10 PST, Andrew Morton said:

> > 2) The PS/2 keyboard death on ppp traffic is still not fixed.
> > Reproducible even on slow GPRS if there's something else (e.g. glxgears)
> > that eats some CPU time. When keyboard is dead, events/0 consomes 100%
> > of CPU. Nothing in dmesg. If you outline some suspicious pieces of code,
> > I will insert printks there in order to debug this.
>
> input guys cc'ed.

Getting myself on the cc: list, as I've seen this one on 2.6.14-rc5-mm1 (haven't
nailed it on 14-mm1 *yet*, but only been up for 12 hours). Also, some
additional info:

The keyboard is dead, but other stuff still works - I've been able to issue
commands by laborious cut-n-paste into an xterm window. X is still up and
responding, as are all the clients, so it's *not* a hard loop in events/0.

Also, I've had gkrellm running when it hits, and it will show incoming data
rates on the modem of 3.5Mbytes/sec (as opposed to the 5K/sec you'd expect from
a 56k modem). A few times, I've had it go into auto-ambush on an iptables rule,
with the same rule tripping several tens of thousands of times in a row,
which makes me think it's got to do with a short packet (such as an inbound
SYN packet) going into replicator mode and just being handed up from the
device driver over and over, thousands of times....

alt-sysrq still works - I can sysrq-T to get traces, -S to sync, -B to reboot
and so on, and the output gets through klogd and syslogd and into /var/adm/messages.

I'm able to often trigger the bug by opening a new tab in Firefox, as that (a)
involves small SYN+ACK packets coming back and (b) a Firefox bug causes it to
chew CPU when displaying a page in a tab....

I'm willing to test-drive any debugging/patches needed, as this is probably the
single biggest stability hit I have in -mm at the moment.

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