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

[Andi Kleen <ak@linux.intel.com>]

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.

Also power of two summaries at a bit odd, but ok.

> For Processor Information printout:
> 
>     [   90.968381] Summary Processor Information for CPUS: 0-639
>     [   90.972033] Genuine Intel(R) CPU    0000 @ 2.13GHz stepping 04

It would be good to print family/model in this line

>     [   90.981402] CPU: L1 I cache: 32K, L1 D cache: 32K
>     [   90.985888] CPU: L2 cache: 256K
>     [   90.988032] CPU: L3 cache: 24576K

I would recommend to drop the cache information; this can be easily
gotten at runtime and is often implied in the CPU name anyways
(and especially L1 and increasingly L2 too change only very rarely)

>     [   90.992032] MIN 4266.68 BogoMIPS (lpj=8533371)
>     [   91.000033] MAX 4267.89 BogoMIPS (lpj=8535789)

Perhaps an average too? You could put all that on one line.


> These lines have been moved to loglevel KERN_DEBUG:
> 
>     CPU: Physical Processor ID:
>     CPU: Processor Core ID:
>     CPU %d/0x%x -> Node %d
>     <cache line sizes per cpu>

I think you can just remove them.

>     CPUx is down

This should be still printed if there's a timeout, or rather print
a "CPUx is not down" message. Right now there's no timeout detection on shutdown, but
I guess that wouldn't be too hard to add.

-Andi