[haiku-development] Re: Fixing get_cpu_model_string(), Ticket 3541

  • From: Urias McCullough <umccullough@xxxxxxxxx>
  • To: haiku-development@xxxxxxxxxxxxx
  • Date: Sat, 20 Jun 2009 06:45:33 -0700

On Sat, Jun 20, 2009 at 4:02 AM, Christian
Packmann<Christian.Packmann@xxxxxx> wrote:
> Haiku will mis-identify many Core2 CPUs, see e.g.
> http://dev.haiku-os.org/ticket/3541. This also affects my Core2Quad 9550
> which shows as Core2 Extreme.
>
> The problem is get_cpu_model_string() in
> trunk/headers/private/shared/cpu_type.h
> http://svn.berlios.de/viewcvs/haiku/haiku/trunk/headers/private/shared/cpu_type.h?revision=30106&view=markup
>
> CPU strings are assigned via the processor signature here, but this is not
> precise; the signature is determined by a specific die stepping, but the
> same dies are often used for different CPU models.
>
> The only solution I can see for this is using the CPUID brand string
> functions 0xx80000002-4 for reading the CPUs brand string and then
> processing that string to get something more readable. I've got code for
> that which seems to work reasonably well.
>
> Before:
>
> AMD Sempron(tm) Processor 3000+
> AMD Athlon(tm) 64 Processor 3200+
> AMD Athlon(tm) 64 X2 Dual Core Processor 4200+
> AMD Phenom(tm) 9950 Quad-Core Processor
> Intel(R) Pentium(R) III CPU family 1400MHz
> Intel(R) Pentium(R) 4 CPU 2.80GHz
> Intel(R) Xeon(TM) CPU 3.20GHz
> Intel(R) Pentium(R) M processor 1.70GHz
> Intel(R) Core(TM)2 CPU          4300  @ 1.80GHz
> Intel (R) Core(Tm)2 CPU T5500 @ 1.66Ghz
> Intel(R) Core(TM)2 CPU         T7200  @ 2.00GHz
> Intel(R) Core(TM)2 Duo CPU T9500 @ 2.60GHz
> Intel(R) Core(TM)2 Duo CPU     T9600  @ 2.80GHz
> Intel(R) Core(TM)2 Quad CPU    Q9550  @ 2.83GHz
> Intel(R) Atom(TM) CPU N270   @ 1.60GHz
> VIA Ezra
>
> After:
>
> AMD Sempron
> AMD Athlon 64
> AMD Athlon 64 X2
> AMD Phenom 9950
> Intel Pentium III
> Intel Pentium 4
> Intel Xeon
> Intel Pentium M
> Intel Core2 4300
> Intel Core2 T5500
> Intel Core2 T7200
> Intel Core2 T9500
> Intel Core2 T9600
> Intel Core2 Q9550
> Intel Atom N270
> VIA Ezra

I don't quite understand the reason for having different strings being
returned by the code in cpu_type.h. For friendly-name purposes?

When porting BOINC recently, I really needed the full brand string to
pass to the server as returned by sysinfo (brand string), so I ended
up copy/pasting most of the code from sysinfo's CPU detection logic
into the Haiku-specific code in BOINC. This obviously is undesirable,
but AFAICT, there was no other API for getting this info.

Additionally, I needed the string of features which there is no API for either.

BOINC servers use all this info to determine what optimized client
could/should sent to the individual machine requesting the work.

- Urias

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