Messages in this thread | | | Date | Wed, 27 Oct 2010 16:35:05 -0700 | From | Andrew Morton <> | Subject | Re: [RFC][Patch] Adding kmsg_dump() to reboot/halt/poweroff/emergency_restart path |
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On Tue, 19 Oct 2010 11:51:12 +0300 Artem Bityutskiy <Artem.Bityutskiy@nokia.com> wrote:
> On Tue, 2010-10-19 at 10:52 +0200, ext KOSAKI Motohiro wrote: > > > Hi, > > > > > > Final messages from reboot, halt and poweroff aren't output to disk because klogd/syslogd > > > has been killed and root file system has been turned read-only. > > > > > > Final messages from emergency_restart aren't output to disk as well because system may > > > reboot before klogd/syslogd outputs messages to disk. > > > > > > Therefore, it is better to put kmsg_dumper in reboot/halt/poweroff/emergency_restart path. > > > Any comments/advices are welcome. > > > > I think mtdoops user don't want to dump logs if a system reboot/poweroff > > safely because mtd device have write count limitation. and they are main > > user of kmsg_dump().
mtdoops was the only user until ramoops came along.
> Right, at least this is how we use mtdoops - we log crashes.
Fair enough. So I suppose the existing clients (mtdoops_do_dump and ramoops_do_dump) should be altered to inspect the `reason' argument, and return if it isn't KMSG_DUMP_OOPS, KMSG_DUMP_PANIC or KMSG_DUMP_KEXEC (I assume?)
If that sounds suitable then I'd ask Seiji to update and resend the patch, along with a complete changelog as earlier dicussed.
I'd suggest doing it as two patches, the first of which alters mtdoops and ramoops to perform their actions only for the appropriate `reason' values.
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