lkml.org 
[lkml]   [2011]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v3 4/6] memory: memory notifier error injection module
    Date
    This provides the ability to inject artifical errors to memory hotplug
    notifier chain callbacks. It is controlled through debugfs interface
    under /sys/kernel/debug/memory-notifier-error-inject/

    Each of the files in the directory represents an event which can be failed
    and contains the error code. If the notifier call chain should be failed
    with some events notified, write the error code to the files.

    Example: Inject memory hotplug offline error (-12 == -ENOMEM)

    # cd /sys/kernel/debug/memory-notifier-error-inject
    # echo -12 > MEM_GOING_OFFLINE
    # echo offline > /sys/devices/system/memory/memoryXXX/state
    bash: echo: write error: Cannot allocate memory

    Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
    Cc: Greg KH <greg@kroah.com>
    Cc: linux-mm@kvack.org
    ---
    * v3
    - rewrite to be kernel modules instead of initializing at late_initcall()s
    - notifier priority can be specified as a module parameter

    lib/Kconfig.debug | 20 ++++++++++++++++
    lib/Makefile | 1 +
    lib/memory-notifier-error-inject.c | 45 ++++++++++++++++++++++++++++++++++++
    3 files changed, 66 insertions(+), 0 deletions(-)
    create mode 100644 lib/memory-notifier-error-inject.c

    diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
    index 69ecd50..a2b0856 100644
    --- a/lib/Kconfig.debug
    +++ b/lib/Kconfig.debug
    @@ -1079,6 +1079,26 @@ config PM_NOTIFIER_ERROR_INJECT

    If unsure, say N.

    +config MEMORY_NOTIFIER_ERROR_INJECT
    + tristate "Memory hotplug notifier error injection module"
    + depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
    + help
    + This option provides the ability to inject artifical errors to
    + memory hotplug notifier chain callbacks. It is controlled through
    + debugfs interface.
    +
    + Example: Inject memory hotplug offline error (-12 == -ENOMEM)
    +
    + # cd /sys/kernel/debug/memory-notifier-error-inject
    + # echo -12 > MEM_GOING_OFFLINE
    + # echo offline > /sys/devices/system/memory/memoryXXX/state
    + bash: echo: write error: Cannot allocate memory
    +
    + To compile this code as a module, choose M here: the module will
    + be called memory-notifier-error-inject.
    +
    + If unsure, say N.
    +
    config FAULT_INJECTION
    bool "Fault-injection framework"
    depends on DEBUG_KERNEL
    diff --git a/lib/Makefile b/lib/Makefile
    index 4dca6c0..f28914b 100644
    --- a/lib/Makefile
    +++ b/lib/Makefile
    @@ -91,6 +91,7 @@ obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
    obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
    obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
    obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
    +obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o

    lib-$(CONFIG_GENERIC_BUG) += bug.o

    diff --git a/lib/memory-notifier-error-inject.c b/lib/memory-notifier-error-inject.c
    new file mode 100644
    index 0000000..76f0b94
    --- /dev/null
    +++ b/lib/memory-notifier-error-inject.c
    @@ -0,0 +1,45 @@
    +#include <linux/kernel.h>
    +#include <linux/memory.h>
    +#include <linux/module.h>
    +#include <linux/notifier.h>
    +
    +static int priority;
    +module_param(priority, int, 0);
    +MODULE_PARM_DESC(priority, "specify memory notifier priority");
    +
    +static struct err_inject_notifier_block err_inject_memory_notifier = {
    + .actions = {
    + { ERR_INJECT_NOTIFIER_ACTION(MEM_GOING_ONLINE) },
    + { ERR_INJECT_NOTIFIER_ACTION(MEM_GOING_OFFLINE) },
    + {}
    + }
    +};
    +
    +static int err_inject_init(void)
    +{
    + int err;
    +
    + err = err_inject_notifier_block_init(&err_inject_memory_notifier,
    + "memory-notifier-error-inject", priority);
    + if (err)
    + return err;
    +
    + err = register_memory_notifier(&err_inject_memory_notifier.nb);
    + if (err)
    + err_inject_notifier_block_cleanup(&err_inject_memory_notifier);
    +
    + return err;
    +}
    +
    +static void err_inject_exit(void)
    +{
    + unregister_memory_notifier(&err_inject_memory_notifier.nb);
    + err_inject_notifier_block_cleanup(&err_inject_memory_notifier);
    +}
    +
    +module_init(err_inject_init);
    +module_exit(err_inject_exit);
    +
    +MODULE_DESCRIPTION("memory notifier error injection module");
    +MODULE_LICENSE("GPL");
    +MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
    --
    1.7.4.4


    \
     
     \ /
      Last update: 2011-07-23 10:53    [W:0.039 / U:0.588 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site