module param for CPU_NOTIFIER_ERROR_INJECT

module param for CPU_NOTIFIER_ERROR_INJECT

[Justin P. Mattock]

hello,
I am playing around with CPU_NOTIFIER_ERROR_INJECT and am noticing that

example 2
# modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
# echo 1 > /sys/devices/system/cpu/cpu1/online
bash: echo: write error: No such file or directory

is not working for me, or atleast is not showing me any info that it is 
working.

the other proceedure does work:

example 1
# modprobe cpu-notifier-error-inject cpu_down_prepare_error=-1
# echo 0 > /sys/devices/system/cpu/cpu1/online
bash: echo: write error: Operation not permitted

dmesg shows:
[ 2427.924405] Injecting error (-1) at cpu notifier
[ 2427.930569] _cpu_down: attempt to take down CPU 1 failed


any ideas on what I need to do or is this working, and am I not seeing 
anything in dmesg?

Justin P. Mattock

Re: module param for CPU_NOTIFIER_ERROR_INJECT

[Akinobu Mita]

2011/8/22 Justin P. Mattock <justinmattock@gmail.com>:

> example 2
> # modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
> # echo 1 > /sys/devices/system/cpu/cpu1/online
> bash: echo: write error: No such file or directory
>
> is not working for me, or atleast is not showing me any info that it is
> working.

I suspect that cpu-notifier-error-inject module is already loaded and
the module parameter is just ignored when you run above commands.

Please retry it after rmmod or change that parameter through
/sys/module/cpu-error-inject/parameters/cpu_up_prepare_error.

Re: module param for CPU_NOTIFIER_ERROR_INJECT

[Justin P. Mattock]

On 08/22/2011 09:41 AM, Justin Mattock wrote:
> Cool.. I will retry on this and let you know.
>
> On Aug 22, 2011 5:48 AM, "Akinobu Mita" <akinobu.mita@gmail.com
> <mailto:akinobu.mita@gmail.com>> wrote:
>  > 2011/8/22 Justin P. Mattock <justinmattock@gmail.com
> <mailto:justinmattock@gmail.com>>:
>  >
>  >> example 2
>  >> # modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
>  >> # echo 1 > /sys/devices/system/cpu/cpu1/online
>  >> bash: echo: write error: No such file or directory
>  >>
>  >> is not working for me, or atleast is not showing me any info that it is
>  >> working.
>  >
>  > I suspect that cpu-notifier-error-inject module is already loaded and
>  > the module parameter is just ignored when you run above commands.
>  >
>  > Please retry it after rmmod or change that parameter through
>  > /sys/module/cpu-error-inject/parameters/cpu_up_prepare_error.
>

cool, Thanks for the help.. not sure if this is correct, but I had to 
shutdown one of the cores, then execute the cammand to get any response..:

echo 0 > /sys/devices/system/cpu/cpu1/online
modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
echo 1 > /sys/devices/system/cpu/cpu1/online

[ 4205.955592] Injecting error (-2) at cpu notifier
[ 4205.955601] _cpu_up: attempt to bring up CPU 1 failed

so it is working!

Justin P. Mattock