Re: [PATCH] x86_64: Limit the number of processor bootup messages

From: Ingo Molnar
Date: Mon Nov 02 2009 - 14:36:47 EST

* Mike Travis <travis@xxxxxxx> wrote:

> Andi Kleen wrote:
>> Mike Travis wrote:
>>> This set of patches limits the number of repetitious messages which
>>> contain
>>> no additional information. Much of this information is obtainable
>>> from the
>>> /proc and /sysfs. Most of the messages are also sent to the kernel log
>>> buffer as KERN_DEBUG messages so it can be used to examine more
>>> closely any
>>> details specific to a processor.
>> What would be good is to put the information from the booting CPUs
>> into some buffer and print it visibly if there's a timeout detected on
>> the BP.
> What do you think of this idea.... Add a "mark kernel log buffer"
> function, and then if any KERN_NOTE or above happens, it sends the
> marked info from the kernel log buffer to the console before the
> current message. Set the marker to '0' to clear.

That's _way_ too complex really, for little benefit. (If there's a boot
hang people will re-try anyway (and this time with a serial console
attached or so), and they can add various boot options to increase
verbosity - depending in which phase the bootup hung.)

So please go with the simple solution i suggested days ago: print stuff
on the boot CPU but after that only a single line per AP CPU.

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