Re: [PATCH] smpboot: cachesize comparison fix in smp_tune_scheduling()

[Jarek Poplawski <jarkao2@o2.pl>]

On Thu, May 24, 2007 at 04:02:07PM -0700, Andrew Morton wrote:
> On Thu, 24 May 2007 12:33:23 +0200
> Jarek Poplawski <jarkao2@o2.pl> wrote:
> 
> > 
> > smpboot: cachesize comparison fix in smp_tune_scheduling()
> > 
> > boot_cpu_data.x86_cache_size is signed int and can be < 0 too.
...
> Under what conditions can boot_cpu_data.x86_cache_size be negative?
> 
> Have negative values of boot_cpu_data.x86_cache_size been observed in
> practice?

Sorry, but IMHO every observations are only kind of illusions,
and should have no influence on any serious science, including
computer science.

But, from smpboot.c history:

"[PATCH] i386: Clean up smp_tune_scheduling()
Adrian Bunk [Thu, 7 Dec 2006 01:14:19 +0000 (02:14 +0100)]
- remove the write-only local variable "bandwidth"
- don't set "max_cache_size" in the (cachesize < 0) case:
  that's already handled in kernel/sched.c:measure_migration_cost()"

So, it seems such strange phenomenon could've been observed
long time ago...

Thanks,
Jarek P.