Re: [PATCH] powerpc: opal-msglog: Report size of memcons log

[Joel Stanley <joel@jms.id.au>]

On Wed, Jan 25, 2017 at 1:33 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> Michael Ellerman <mpe@ellerman.id.au> writes:
>
>> Joel Stanley <joel@jms.id.au> writes:
>>
>>> The OPAL memory console is reported to be size zero, as we do not
>>> initialise the struct attr with any size information due to the size
>>> being variable. This leads users to think that the console is empty.
>>
>> Hmm OK. That is a general property of /proc and /sys files that are
>> dynamically generated, so users probably need to get used to it :)
>>
>>> Instead report the maximum size.
>>
>> But OK. That sounds sane enough. My only worry is that it might confuse
>> some tools, ie. the file claims to be x bytes but is actually smaller.
>> But I guess that can actually happen anyway with any file.
>>
>> So I'll merge this and stop blabbing :)
>
> Hmm, but then I get:
>
>   $ ls -la msglog
>   -r--r--r-- 1 root root 4503599627370496 Jan 25 13:09 msglog
>
> I know firmware likes to spit out lots of messages, but 4PB seems a bit
> large :P
>
> I fixed it with the patch below which I'll fold in, resulting in:
>
>   $ ls -la msglog
>   -r--r--r-- 1 root root 1048576 Jan 25 13:30 msglog
>
>
> Which seems more likely.

My bad. In my excitement I forgot to mention that this was just an
idea, and I had not boot tested it.

Thanks for testing it and finding the bug.

Cheers,

Joel