Problems with 2.4.4 crash dumps

[Simon Falvey <simon.falvey@xxxxxxxxxxx>]

Hi.

This may be a bit of a newbie question. I have only just discovered lkcd and
I think I am going to get a lot of value out of it in my job (surely not?
work related linux who ever heard of such a thing).

I applied by hand the patch for 2.4.1 to the 2.4.4 kernel running under
RH7.1. I have also placed a hook under the Magic sysrq key sequence hook a
call to panic() on demand (This will be very useful for diagnosing hung
systems).

The system falls into the dump_execute  routine which then calls
alloc_kiovec in the section "start walking through the page tables ". The
system then does not return (to dump_execute)  from this. On the screen it
reports a BUG in slab.c line 1073 which is a call to BUG(). It then returns
back to panic() (I think)  without finishing the dump but it does finish the
panic and reboot the system. Such that..

                        /* debug: print markers to trace the problem */
                        printk("Marker 1 ");
                /* start walking through the page tables */
                if (alloc_kiovec(1, &dump_iobuf)) {
                                printk("Marker 2 ");
                        printk("\n" KERN_WARNING
                                "alloc_kiovec() failed!");
                } else {
                printk("Marker 4 ");

Neither Marker 2 nor Marker 4 are reached.

I am entirely satisfied that the patch has applied correctly. The
configuration of vmdump is a level 4 with compression to /dev/hda6 (the swap
dev).

Has anything similar been seen before? Has any one any ideas about the
problem?


Also any idea when the lkcd code will make the standard linux code base?

Thanks

Simon


Simon Falvey
Online Product Support Specialist
VERITAS Software UK.
Tel: +44 118  918 8105