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

From: Mike Travis
Date: Mon Oct 26 2009 - 14:33:42 EST




Ingo Molnar wrote:
* Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:

On Sun, 25 Oct 2009 17:37:04 +0100
Ingo Molnar <mingo@xxxxxxx> wrote:

Having the precise microcode version printed (or exposed somewhere in /sys) is useful - sometimes when there's a weird crash in some
prototype CPU one of the first questions from hw vendors is 'which
precise microcode version was that?'.
something like /sys/devices/system/cpu/cpu0/microcode/version ?

(yes that is there today ;-)

yeah, i used that for a bug recently.

Nevertheless it makes sense to print the boot CPU message too - for bugs that crash before we can read out /sys/devices/system/cpu/cpu0/microcode/version.

Ingo

I added the printout of the first few cpus. I had thought that maybe
printing the cpu info for each new socket discovered, perhaps reducing
that to each new blade or chassis as the number grew, but again it quickly
became more complex that I thought was necessary...(?)

If you get the first cpu started ok, then using a kernel debugger like
KDB, you can usually get the remaining information.

Thanks,
Mike
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