100 lines
3.3 KiB
Plaintext
100 lines
3.3 KiB
Plaintext
|
Notifier error injection
|
||
|
|
========================
|
||
|
|
|
||
|
|
Notifier error injection provides the ability to inject artifical errors to
|
||
|
|
specified notifier chain callbacks. It is useful to test the error handling of
|
||
|
|
notifier call chain failures which is rarely executed. There are kernel
|
||
|
|
modules that can be used to test the following notifiers.
|
||
|
|
|
||
|
|
* CPU notifier
|
||
|
|
* PM notifier
|
||
|
|
* Memory hotplug notifier
|
||
|
|
* powerpc pSeries reconfig notifier
|
||
|
|
|
||
|
|
CPU notifier error injection module
|
||
|
|
-----------------------------------
|
||
|
|
This feature can be used to test the error handling of the CPU notifiers by
|
||
|
|
injecting artifical errors to CPU notifier chain callbacks.
|
||
|
|
|
||
|
|
If the notifier call chain should be failed with some events notified, write
|
||
|
|
the error code to debugfs interface
|
||
|
|
/sys/kernel/debug/notifier-error-inject/cpu/actions/<notifier event>/error
|
||
|
|
|
||
|
|
Possible CPU notifier events to be failed are:
|
||
|
|
|
||
|
|
* CPU_UP_PREPARE
|
||
|
|
* CPU_UP_PREPARE_FROZEN
|
||
|
|
* CPU_DOWN_PREPARE
|
||
|
|
* CPU_DOWN_PREPARE_FROZEN
|
||
|
|
|
||
|
|
Example1: Inject CPU offline error (-1 == -EPERM)
|
||
|
|
|
||
|
|
# cd /sys/kernel/debug/notifier-error-inject/cpu
|
||
|
|
# echo -1 > actions/CPU_DOWN_PREPARE/error
|
||
|
|
# echo 0 > /sys/devices/system/cpu/cpu1/online
|
||
|
|
bash: echo: write error: Operation not permitted
|
||
|
|
|
||
|
|
Example2: inject CPU online error (-2 == -ENOENT)
|
||
|
|
|
||
|
|
# echo -2 > actions/CPU_UP_PREPARE/error
|
||
|
|
# echo 1 > /sys/devices/system/cpu/cpu1/online
|
||
|
|
bash: echo: write error: No such file or directory
|
||
|
|
|
||
|
|
PM notifier error injection module
|
||
|
|
----------------------------------
|
||
|
|
This feature is controlled through debugfs interface
|
||
|
|
/sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error
|
||
|
|
|
||
|
|
Possible PM notifier events to be failed are:
|
||
|
|
|
||
|
|
* PM_HIBERNATION_PREPARE
|
||
|
|
* PM_SUSPEND_PREPARE
|
||
|
|
* PM_RESTORE_PREPARE
|
||
|
|
|
||
|
|
Example: Inject PM suspend error (-12 = -ENOMEM)
|
||
|
|
|
||
|
|
# cd /sys/kernel/debug/notifier-error-inject/pm/
|
||
|
|
# echo -12 > actions/PM_SUSPEND_PREPARE/error
|
||
|
|
# echo mem > /sys/power/state
|
||
|
|
bash: echo: write error: Cannot allocate memory
|
||
|
|
|
||
|
|
Memory hotplug notifier error injection module
|
||
|
|
----------------------------------------------
|
||
|
|
This feature is controlled through debugfs interface
|
||
|
|
/sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error
|
||
|
|
|
||
|
|
Possible memory notifier events to be failed are:
|
||
|
|
|
||
|
|
* MEM_GOING_ONLINE
|
||
|
|
* MEM_GOING_OFFLINE
|
||
|
|
|
||
|
|
Example: Inject memory hotplug offline error (-12 == -ENOMEM)
|
||
|
|
|
||
|
|
# cd /sys/kernel/debug/notifier-error-inject/memory
|
||
|
|
# echo -12 > actions/MEM_GOING_OFFLINE/error
|
||
|
|
# echo offline > /sys/devices/system/memory/memoryXXX/state
|
||
|
|
bash: echo: write error: Cannot allocate memory
|
||
|
|
|
||
|
|
powerpc pSeries reconfig notifier error injection module
|
||
|
|
--------------------------------------------------------
|
||
|
|
This feature is controlled through debugfs interface
|
||
|
|
/sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error
|
||
|
|
|
||
|
|
Possible pSeries reconfig notifier events to be failed are:
|
||
|
|
|
||
|
|
* PSERIES_RECONFIG_ADD
|
||
|
|
* PSERIES_RECONFIG_REMOVE
|
||
|
|
* PSERIES_DRCONF_MEM_ADD
|
||
|
|
* PSERIES_DRCONF_MEM_REMOVE
|
||
|
|
|
||
|
|
For more usage examples
|
||
|
|
-----------------------
|
||
|
|
There are tools/testing/selftests using the notifier error injection features
|
||
|
|
for CPU and memory notifiers.
|
||
|
|
|
||
|
|
* tools/testing/selftests/cpu-hotplug/on-off-test.sh
|
||
|
|
* tools/testing/selftests/memory-hotplug/on-off-test.sh
|
||
|
|
|
||
|
|
These scripts first do simple online and offline tests and then do fault
|
||
|
|
injection tests if notifier error injection module is available.
|