> > > Hi,
> > >
> > > Just forcing a crash dump via 'echo c > /proc/sysrq-trigger'
results in a crash
> > > dump that has no tasks saved. I see _lots_ of these errors when loading
the
> > > dump with the latest crash from the git repo:
> > >
> > > crash: page excluded: kernel virtual address: ffff88103c5a9000 type:
"fill_task_struct"
> > > WARNING: active task ffff881078a04340 on cpu 3 not found in PID hash
> > >
> > > Then nothing is in the dump:
> > >
> > > crash> ps
> > > PID PPID CPU TASK ST %MEM VSZ RSS COMM
> > > > 0 0 0 ffffffff81c0f4c0 RU 0.0 0 0
[swapper/0]
> > > crash>
> > >
> > > Any ideas?
> > >
> > > I'm using top-o-tree from Dave's git repo
> > >
https://github.com/crash-utility/crash.git:
> > >
> > > commit 04ab5c560a58246e782509d99214afcaf8462b4c
> > > Author: Dave Anderson <anderson(a)redhat.com>
> > > Date: Tue Mar 1 16:16:48 2016 -0500
> > >
> > > Put 2016 copyright in initial banner.
> > >
> > >
> > > Thanks,
> > >
> > > Steve.
> >
> > If you have configured kdump to use makedumpfile -d31, it is probably this:
> >
> > [Crash-utility] makedumpfile: 4.5 kernel commit breaks page filtering
> >
https://www.redhat.com/archives/crash-utility/2016-February/msg00009.html
> >
> > > PS: I'm not on the crash-utility list, so please include my email in
any
> > > replies.
> >
> > PS: if you're using crash on bleeding edge kernels, you might want to join
> > the list, at least in digest mode.
>
> Thanks Dave. I've joined. :)
>
> I changed the makedumpfile line in /etc/init.d/kdump from -d 31 to -d 17,
> then removed the kdump initrd from /boot, and restarted kdump to generate
> the new initrd file. I then rebooted, and produced a new crash dump. But
> I'm still seeing the same issue.
>
> Am I doing the correct procedure for forcing makedumpfile to use -d17?
I think so, yes. And downgrading to -d17 seems to have worked, at least for
the two reporter on this list. You can verify that the -d configuration is as
expected by entering:
crash> help -D | grep dump_level
Hmm: still using 31:
crash> help -D|grep dump_level
dump_level: 31 (0x1f)
(DUMP_EXCLUDE_ZERO|DUMP_EXCLUDE_CACHE|DUMP_EXCLUDE_CACHE_PRI|DUMP_EXCLUDE_USER_DATA|DUMP_EXCLUDE_FREE)
crash>
Apparently the makedumpfile parameters being used are not the ones in /etc/init.d/kdump.