2.4.21 smp: system lockup

Hi,

I recently experienced a lockup on an SMP 2.4.21 kernel (vanilla).

The machine was under very heavy IO at the time. (a full backup was in progress). gzipped Alt+sysrq+t output is attached. I forgot Alt+sysrq+P unfortunatly.

iptables was still functional, it still responded to pings, but everything else was locked up. obviously sysrq was still working. I managed to reboot it with sysrq+b over the serial line.

the machine has been in production for a while and has run in the past for almost 2 months w/o any problems, so I don't believe it's hardware related.

A similar lockup happened once with the redhat 2.4.20-13.9 kernel. I blamed that on all the extra patches present and switched to 2.4.21 hoping that it would alleviate the problem.

PS: I'm not an linux-kernel so please CC me directly.

-m

Hi there,

just realised that I forgot to run ksymoops over the sysrq+t output.

the resolved output is attached. (it's big, so I had to gzip it.i sorry ).

Also, I was wondering if the deadlock I encountered might whave been the IO-pausing under SMP systems that people have been talking about?

thanks in advance.

-m

Quoted 23 lines · Marc Heckmann

Hi,

I recently experienced a lockup on an SMP 2.4.21 kernel (vanilla).

The machine was under very heavy IO at the time. (a full backup was in progress). gzipped Alt+sysrq+t output is attached. I forgot Alt+sysrq+P unfortunatly.

iptables was still functional, it still responded to pings, but everything else was locked up. obviously sysrq was still working. I managed to reboot it with sysrq+b over the serial line.

the machine has been in production for a while and has run in the past for almost 2 months w/o any problems, so I don't believe it's hardware related.

A similar lockup happened once with the redhat 2.4.20-13.9 kernel. I blamed that on all the extra patches present and switched to 2.4.21 hoping that it would alleviate the problem.

PS: I'm not an linux-kernel so please CC me directly.

-m