cvs commit: src/sys/alpha/alpha mp_machdep.c

[Jeff Roberson]

On Mon, 1 Dec 2003, John Baldwin wrote:

>
> On 01-Dec-2003 Jeff Roberson wrote:
> > On Mon, 1 Dec 2003, John Baldwin wrote:
> >
> >>
> >> On 30-Nov-2003 Jeff Roberson wrote:
> >> > jeff        2003/11/30 14:08:24 PST
> >> >
> >> >   FreeBSD src repository
> >> >
> >> >   Modified files:
> >> >     sys/alpha/alpha      mp_machdep.c
> >> >   Log:
> >> >    - Set mp_maxid in a way that is consistent with every other arch.  It is
> >> >      one more than the last valid 'cpuid'.
> >> >
> >> >   Approved by:    re (rwatson)
> >>
> >> Eh?  No it's not.  All that needs to be true is that for every processor,
> >> PCPU_GET(cpuid) <= mp_maxid.
> >>
> >> It can be equal to the highest ID and should be so for most cases.
> >
> > From x86's mp_machdep:
> >         mp_maxid = MAXCPU;
>
> That's a bug.
>
> > ia64
> > mp_maxid = min(mp_ncpus, MAXCPU) - 1;
>
> This is correct.  Note - 1.
>
> > sparc64
> >         cpus = 0;
> >         root = OF_peer(0);
> >         for (child = OF_child(root); child != 0; child = OF_peer(child)) {
> >                 if (OF_getprop(child, "device_type", buf, sizeof(buf)) > 0
> > &&
> >                     strcmp(buf, "cpu") == 0)
> >                         cpus++;
> >         }
> >         mp_maxid = cpus;
>
> This should be cpus - 1.
>
> > And I just changed amd64 and alpha to mean maxid + 1.  Damn. it looks like
> > just sparc64 and x86 were wrong.  Maybe I should change those to mean the
> > right thing, and backout the changes to uma.  yack.
>
> Heh.  I am already waiting for approval from re@ to fix x86.  That was
> definitely my bug.

Well, since ULE and UMA are the only two subsystems which make use of
mp_maxid, can I request that it be one over the maximum id so that I can
use it in loops like:
for (i = 0; i < mp_maxid; i++) {

Otherwise I guess I can do <=.  If you fix x86, can you fix alpha and
amd64, and uma and ule? :-)

>
> --
>
> John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
> "Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/
>