linux/drivers/mtd/mtdoops.c

451 lines
12 KiB

kmsg_dump: constrain mtdoops and ramoops to perform their actions only for KMSG_DUMP_PANIC This series aims to develop logging facility for enterprise use. It is important to save kernel messages reliably on enterprise system because they are helpful for diagnosing system. This series add kmsg_dump() to the paths loosing kernel messages. The use case is the following. [Use case of reboot/poweroff/halt/emergency_restart] My company has often experienced the followings in our support service. - Customer's system suddenly reboots. - Customers ask us to investigate the reason of the reboot. We recognize the fact itself because boot messages remain in /var/log/messages. However, we can't investigate the reason why the system rebooted, because the last messages don't remain. And off course we can't explain the reason. We can solve above problem with this patch as follows. Case1: reboot with command - We can see "Restarting system with command:" or ""Restarting system.". Case2: halt with command - We can see "System halted.". Case3: poweroff with command - We can see " Power down.". Case4: emergency_restart with sysrq. - We can see "Sysrq:" outputted in __handle_sysrq(). Case5: emergency_restart with softdog. - We can see "Initiating system reboot" in watchdog_fire(). So, we can distinguish the reason of reboot, poweroff, halt and emergency_restart. If customer executed reboot command, you may think the customer should know the fact. However, they often claim they don't execute the command when they rebooted system by mistake. No message remains on the current Linux kernel, so we can't show the proof to the customer. This patch improves this situation. This patch: Alters mtdoops and ramoops to perform their actions only for KMSG_DUMP_PANIC, KMSG_DUMP_OOPS and KMSG_DUMP_KEXEC because they would like to log crashes only. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marco Stornelli <marco.stornelli@gmail.com> Reviewed-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12 16:59:29 -08:00
workqueue: deprecate flush[_delayed]_work_sync() flush[_delayed]_work_sync() are now spurious. Mark them deprecated and convert all users to flush[_delayed]_work(). If you're cc'd and wondering what's going on: Now all workqueues are non-reentrant and the regular flushes guarantee that the work item is not pending or running on any CPU on return, so there's no reason to use the sync flushes at all and they're going away. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mattia Dongili <malattia@linux.it> Cc: Kent Yoder <key@linux.vnet.ibm.com> Cc: David Airlie <airlied@linux.ie> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Bryan Wu <bryan.wu@canonical.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-wireless@vger.kernel.org Cc: Anton Vorontsov <cbou@mail.ru> Cc: Sangbeom Kim <sbkim73@samsung.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Petr Vandrovec <petr@vandrovec.name> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Avi Kivity <avi@redhat.com>
2012-08-20 14:51:24 -07:00