Re: 3.13.5 : rm -rf running forever, one cpu at approx 100%

From: Gene Heskett
Date: Thu Feb 27 2014 - 06:30:19 EST


On Wednesday 26 February 2014, Mike Galbraith wrote:
>On Thu, 2014-02-27 at 03:45 +0000, Ken Moffat wrote:
>> On Thu, Feb 27, 2014 at 04:26:35AM +0100, Mike Galbraith wrote:
>> > I would start with strace to see if a task is looping in userspace,
>> > then move on to perf top -g -p <pid> (or perf record/report) to peek
>> > at what it's up to in the kernel. Once you have the where,
>> > trace_printk() is the best thing since sliced bread (which ranks
>> > just below printk()).
>> >
>> > -Mike
>>
>> Thanks. I'll need to build perf.
>
>You may want to build the kernel with frame-pointers too, for easy gdb
>list *0x(hexnum) of *func()+0x(hexoffset) use. Crash is also pretty
>handy both for rummaging live via crash vmlinux /proc/kcore, and for
>leisurely postmortem analysis if you set the box up to crashdump in
>advance, and force a dump (poke sysrq-c or echo c > /proc/sysrq-trigger)
>when you see the bad thing happen. Crash has all kinds of goodies,
>including invocation of gdb.
>
>-Mike

It doesn't look as if I'll have to guys. Amanda is about 1/2 done and
running normally by switching from tar-1.22 to tar-1.27. So I'm going to
toddle off in the general direction of a bed and let amanda send me an
email when its done.

And it did, including some "strange" reports I have yet to decipher. Diffs
in the tar's probably. But it did not hang.

Cheers, Gene
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

NOTICE: Will pay 100 USD for an HP-4815A defective but
complete probe assembly.

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