Re: [PATCH v2 4/5] x86/mce: Simplify flow when handling recoverable memory errors

[Andy Lutomirski]

On Tue, Nov 11, 2014 at 10:22 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Tue, Nov 11, 2014 at 09:15:18AM -0800, Andy Lutomirski wrote:
>> Oh -- does it need to sleep?
>
> Oh yeah, iterates over all tasks and generally async access to VM stuff.
> You can have a look if bored: mm/memory-failure.c
>
> :-)
>
>> I find myself wondering whether a much cleaner solution might be to
>> sync regs and switch stacks before invoking do_machine_check rather
>> than afterwards.  Then do_machine_check would really be completely
>> non-atomic.  It would add a few lines of asm, though.
>
> That's like wagging the dog.

Wagging this particular dog might shake some loose fur off.  If we did
this for all paranoid entries, then paranoid_userspace could just be
deleted.  :)

>
> I'd prefer much more to actually have a mechanism to do something to
> tasks before scheduling them in.

Like task_work_add?

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/