Re: [PATCH v3 0/6] allow ramoops to collect all kmesg_dump events

From: Pavel Tatashin
Date: Wed May 13 2020 - 10:35:56 EST


> > + reason: panic, oops, emergency, shutdown (ordered by severity)
> > + handling: restart, halt, poweroff
> >
> > Or we might just replace KMSG_DUMP_RESTART, KMSG_DUMP_HALT,
> > KMSG_DUMP_POWEROFF with a single KMSG_DUMP_SHUTDOWN.
> >
> > Then the max reason variable would make sense.
>
> That would work for me, yeah. Pavel, is that enough granularity for you?
>

Yes, I like the second approach: where we combine all shutdown type
events into a single type.
max_reason will have 4 levels:

KMSG_DUMP_PANIC,
KMSG_DUMP_OOPS,
KMSG_DUMP_EMERG,
KMSG_DUMP_SHUTDOWN,

If needed it is possible to determine from dmesg logs what kind of
shutdown was taken, because there is a message logged right before
every kmsg_dump() for these events:

249 if (!cmd)
250 pr_emerg("Restarting system\n");
251 else
252 pr_emerg("Restarting system with command '%s'\n", cmd);
253 kmsg_dump(KMSG_DUMP_RESTART);

276 pr_emerg("System halted\n");
277 kmsg_dump(KMSG_DUMP_HALT);

294 pr_emerg("Power down\n");
295 kmsg_dump(KMSG_DUMP_POWEROFF);

Kees, I will submit a new series with these changes soon.

Thank you,
Pasha