On Sunday, July 08, 2012, Akinobu Mita wrote: > fault-injection-notifier-error-injection.patch in -mm tree adds > notifier error injection. > > This adds Documentation/fault-injection/notifier-error-inject.txt > which describes its feature and usage examples. > > Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com> > Cc: Pavel Machek <pa...@ucw.cz> > Cc: "Rafael J. Wysocki" <r...@sisk.pl> > Cc: Greg KH <g...@kroah.com> > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Cc: Paul Mackerras <pau...@samba.org> > Cc: Michael Ellerman <mich...@ellerman.id.au> > Cc: Dave Jones <da...@redhat.com>
ACK for the PM part. Thanks, Rafael > --- > .../fault-injection/notifier-error-inject.txt | 99 > ++++++++++++++++++++ > 1 file changed, 99 insertions(+) > create mode 100644 Documentation/fault-injection/notifier-error-inject.txt > > diff --git a/Documentation/fault-injection/notifier-error-inject.txt > b/Documentation/fault-injection/notifier-error-inject.txt > new file mode 100644 > index 0000000..c83526c > --- /dev/null > +++ b/Documentation/fault-injection/notifier-error-inject.txt > @@ -0,0 +1,99 @@ > +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. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
