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From: Bronek Kozicki <brok@incorrekt.com>
To: Randy Dunlap <rdunlap@infradead.org>, linux-kernel@vger.kernel.org
Cc: cgroups@vger.kernel.org
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Subject: Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
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In-Reply-To: <54a16e07-70e6-adda-ebdb-06349b4f8e86@infradead.org>
Date: Sun, 17 Dec 2017 18:48:16 +0000
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FWIW, I can do "cat" . I get a single number seemingly followed by an
infinite stream of 0s (I tried wc -l, but did not want to wait very long
and killed it). Here is what it looks like, if limited by "head":

root@gdansk ~ # cat
'/sys/fs/cgroup/unified/machine.slice/machine-qemu\x2d1\x2dkartuzy\x2dspice.scope/cgroup.procs'
| head
10649
0
0
0
0
0
0
0
0
0
root@gdansk ~ #

PID 10649 is indeed qemu process running the virtual machine in
question:

root@gdansk ~ # ps lw 10649
F   UID   PID  PPID PRI  NI    VSZ   RSS WCHAN  STAT TTY        TIME
COMMAND
6     0 10649     1  20   0 4815836 60252 -     Sl   ?          2:56
/usr/bin/qemu-system-x86_64 -name
guest=kartuzy-spice,process=qemu:kartuzy-spice,debug-threads=on -S
-object se


Sorry about taint by ZFS, but there is nothing I can do, it is my root
filesystem. Since I am the only user of the package in question I could
cheat and replace the license for the build of the ZFS module, but I do
not see how that might help.


B.