On Thu, 10 Mar 2016 17:34:54 +0000 Ben Hutchings wrote:
> On Thu, 2016-03-10 at 17:32 +0100, Harry Junior wrote:
>> Package: linux-image-4.4.0-1-amd64
>> Version: 4.4.4-1
>> Severity: critical
>> Justification: renders system unusable
>>
>>
>> When I run the following commands, the system freezes:
>>
>> # echo 0 | tee /sys/devices/system/cpu/cpu*/online && echo 1 | sudo
>> tee /sys/devices/system/cpu/cpu*/online
>>
>> The system freezes randomly when the CPUs are being onlined or
>> offlined. The system is installed on a VMware virtual machine with 4
>> processors. Here's a stacktrace of the infinite loop:
> [...]
>
> You just asked to offline all CPUs, making the system unusable. Â I
> don't see any bug here.
I'm sorry to disagree, but the CPU0 can't be offlined and remains online:
$ ls -l /sys/devices/system/cpu/ | grep cpu | head -4
drwxr-xr-x 6 root root 0 Mar 10 18:41 cpu0
drwxr-xr-x 6 root root 0 Mar 10 18:41 cpu1
drwxr-xr-x 6 root root 0 Mar 10 18:41 cpu2
drwxr-xr-x 6 root root 0 Mar 10 18:41 cpu3
$ ls -l /sys/devices/system/cpu/cpu*/online
-rw-r--r-- 1 root root 4096 Mar 10 18:40 /sys/devices/system/cpu/cpu1/online
-rw-r--r-- 1 root root 4096 Mar 10 18:40 /sys/devices/system/cpu/cpu2/online
-rw-r--r-- 1 root root 4096 Mar 10 18:40 /sys/devices/system/cpu/cpu3/online
