Re: [PATCH 6/8] SGI x86_64 UV: Limit the number of microcode messages

From: Dmitry Adamushko
Date: Sat Oct 24 2009 - 18:45:36 EST


2009/10/24 Tigran Aivazian <tigran@xxxxxxxxxxxxxxxxxxxx>:
> On Sat, 24 Oct 2009, Dmitry Adamushko wrote:
>>>
>>> -       printk(KERN_INFO "microcode: CPU%d sig=0x%x, pf=0x%x,
>>> revision=0x%x\n",
>>> +       if (cpu_num < 4 || !limit_console_output(false))
>>> +               printk(KERN_INFO
>>> +                       "microcode: CPU%d sig=0x%x, pf=0x%x,
>>> revision=0x%x\n",
>>>                        cpu_num, csig->sig, csig->pf, csig->rev);
>>>
>>
>> Hmm, I guess we wouldn't lose a lot by simply removing those messages
>> completely. Per-cpu pf/revision is available via /sys anyway.
>
> The reason for printing them is that the pf (possibly others?) can change by the update and so the log has this info handy.

We might store the old sig/pf/revision set as well, export them via
/sys or/and print them at update-to-new-microcode time.

If it's really so useful to have this info in the log and, at the same
time, to avoid the flood of messages (which, I guess for the majority
of systems, are the same) at startup time, we might delay the printout
until the end of microcode_init(). Then do something like this:

microcode cpu0: up to date version sig, pf, rev // let's say,
it was updated by BIOS
microcode cpus [1 ... 16] : update from sig, pf, rev to sig, pf2, rev2.

Anyway, my humble opinion, is that (at the very least) the current
patch should be accompanied by a similar version for amd.


>
> Kind regards
> Tigran


-- Dmitry
--
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/