Date: Mon, 01 Dec 2003 18:09:35 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Jeff Roberson <jroberson@chesapeake.net> Cc: cvs-all@FreeBSD.org Subject: RE: cvs commit: src/sys/alpha/alpha mp_machdep.c Message-ID: <XFMail.20031201180935.jhb@FreeBSD.org> In-Reply-To: <20031201175237.S4201-100000@mail.chesapeake.net>
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On 01-Dec-2003 Jeff Roberson wrote:
>
> 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? :-)
I'll fix all of them and work up a patch tomorrow, sure. :)
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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