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author | Akinobu Mita <akinobu.mita@gmail.com> | 2012-07-30 14:43:10 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 17:25:22 -0700 |
commit | 9579f5bd31a04e80a87a7b58bd52dff6dc68bc99 (patch) | |
tree | a574a53f7829f157ef9ce2b696cc66ffe92bcef9 /lib | |
parent | 048b9c3549790af21eabd06a5ebdad305e75b1c5 (diff) | |
download | lwn-9579f5bd31a04e80a87a7b58bd52dff6dc68bc99.tar.gz lwn-9579f5bd31a04e80a87a7b58bd52dff6dc68bc99.zip |
memory: memory notifier error injection module
This provides the ability to inject artifical errors to memory hotplug
notifier chain callbacks. It is controlled through debugfs interface
under /sys/kernel/debug/notifier-error-inject/memory
If the notifier call chain should be failed with some events notified,
write the error code to "actions/<notifier event>/error".
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
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Kconfig.debug | 23 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/memory-notifier-error-inject.c | 48 |
3 files changed, 72 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c2024d86fb12..35cfd9eef0e0 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1143,6 +1143,29 @@ 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 under /sys/kernel/debug/notifier-error-inject/memory + + If the notifier call chain should be failed with some events + notified, write the error code to "actions/<notifier event>/error". + + 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 + + To compile this code as a module, choose M here: the module will + be called pSeries-reconfig-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 c32c66473ba1..c34719337d26 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -93,6 +93,7 @@ obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-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 000000000000..e6239bf0b0df --- /dev/null +++ b/lib/memory-notifier-error-inject.c @@ -0,0 +1,48 @@ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/memory.h> + +#include "notifier-error-inject.h" + +static int priority; +module_param(priority, int, 0); +MODULE_PARM_DESC(priority, "specify memory notifier priority"); + +static struct notifier_err_inject memory_notifier_err_inject = { + .actions = { + { NOTIFIER_ERR_INJECT_ACTION(MEM_GOING_ONLINE) }, + { NOTIFIER_ERR_INJECT_ACTION(MEM_GOING_OFFLINE) }, + {} + } +}; + +static struct dentry *dir; + +static int err_inject_init(void) +{ + int err; + + dir = notifier_err_inject_init("memory", notifier_err_inject_dir, + &memory_notifier_err_inject, priority); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + err = register_memory_notifier(&memory_notifier_err_inject.nb); + if (err) + debugfs_remove_recursive(dir); + + return err; +} + +static void err_inject_exit(void) +{ + unregister_memory_notifier(&memory_notifier_err_inject.nb); + debugfs_remove_recursive(dir); +} + +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>"); |