Re: [Patch] Output of L1,L2 and L3 cache sizes to /proc/cpuinfo

[H. Peter Anvin]

"Martin.Knoblauch" wrote:
> 
>  After some checking, I could have made the answer a bit less terse:
> 
> - it would require that the kernel is compiled with cpuid [module]
> support
>   - not everybody may want enable this, just for getting one or two
>     harmless numbers.

If so, then that's their problem.  We're not here to solve the problem of
stupid system administrators.

> - you would need a utility with root permission to analyze the cpuid
> info. The
>   cahce info does not seem to be there in clear ascii.

Bullsh*t.  /dev/cpu/%d/cpuid is supposed to be mode 444 (world readable.)

>   - this limits my script to root users, or you need the setuid-bit on
> the
>     utility. Not really good for security.

See above.

> - the cpuid stuff is i386 specific [today]. So are my changes. But
> implementing
>   them for other architectures [if there is interest in the info] would
> not
>   require to also implement the cpuid on other architectures. Which may
> not make any
>   sense at all.
> 
>  So, having the numbers in clear text in the cpuinfo file looks simpler
> and safer to me, although reading /dev/cpu/*/cpuinfo maybe more
> versatile [on i386] - at some cost.
> 
>  Question: are there any utilities or other uses for the cpuid device
> today? Just interested. The kernel seems to work well without it.

That is usually the case with devices -- the kernel doesn't care, why
would it?

	-hpa

-- 
<[e-mail]> at work, <[e-mail]> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt