From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752185Ab1GWIuX (ORCPT ); Sat, 23 Jul 2011 04:50:23 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:51893 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752048Ab1GWIti (ORCPT ); Sat, 23 Jul 2011 04:49:38 -0400 From: Akinobu Mita To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org Cc: Akinobu Mita , Greg KH , linux-mm@kvack.org Subject: [PATCH v3 4/6] memory: memory notifier error injection module Date: Sat, 23 Jul 2011 17:50:58 +0900 Message-Id: <1311411060-30124-5-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1311411060-30124-1-git-send-email-akinobu.mita@gmail.com> References: <1311411060-30124-1-git-send-email-akinobu.mita@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Greg KH 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 +#include +#include +#include + +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 "); -- 1.7.4.4