Subject: Re: [PATCH 7/7] powerpc numa: Consolidate assignment of cpus to nodes

From: Michael Ellerman <[email-masked]>
Date: Wed, 22 Mar 2006 10:34:58 +1100

On Wed, 22 Mar 2006 10:22, Nathan Lynch wrote:
> On Wed, 2006-03-22 at 10:09 +1100, Michael Ellerman wrote:
> > On Wed, 22 Mar 2006 06:16, Nathan Lynch wrote:
> > > On Tue, 2006-03-21 at 10:38 -0800, Dave Hansen wrote:
> > > > By the way, what do the "l" and "h" in front of "cpu" mean anyway?
> > >
> > > "logical" and "hot"?  I dunno, just seemed to be the convention in
> > > other cpu notifiers at the time the code was written.
> >
> > Ouch, that's unfortunate. In the powerpc code hcpu _usually_ means hard
> > cpu number, as opposed to logical (lcpu).
>
> Grep begs to differ:
>
> $ grep -rw hcpu arch/powerpc include/asm-powerpc
> arch/powerpc/kernel/sysfs.c:                                  unsigned long
> action, void *hcpu) arch/powerpc/kernel/sysfs.c:    unsigned int cpu =
> (unsigned int)(long)hcpu; arch/powerpc/mm/numa.c:                      void
> *hcpu)
> arch/powerpc/mm/numa.c: unsigned long lcpu = (unsigned long)hcpu;

You're right, it's actually a mixture of pcpu, hw_cpuid, hardid etc. So there 
should be no confusion by using hcpu for "hot" cpu.

cheers

-- 
Michael Ellerman
IBM OzLabs

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person