Re: Patch procfs cpuinfo

[Bouju Alain]

Hello,

For Intel with HyperThreading 8 I think -> 16 (virtual core).
Linux probably choose 8 to obtain better result.
This is not very clear for me.

http://www.richweb.com/cpu_info

I have apply your change.
With Qemu I obtain 1 processor (I keep the virtual number of core but 
it's easy to change, I can change it)

Alain



On 19/11/2011 23:18, Samuel Thibault wrote:
> Hello,
>
> Bouju Alain, le Sun 13 Nov 2011 12:44:04 +0100, a écrit :
> > /* gcc cpuinfo.c -o cpuinfo `pkg-config --cflags glib-2.0` -lm */
> > #include<glib.h>
> Using glib for /proc is a bit out of question :)
> 16-bit and 32-bit types are available as uint16_t&  uint32_t in
> stdint.h.
>
> The coding style has to follow the GNU Coding Style, e.g. there must be
> a space between the function name and the opening parenthesis. You
> should probably use indent to fix everything automatically.
>
> cpuid is only available on x86, so the code should be put in some x86/
> directory, and ideally compiled only on x86.
>
> No need to put __volatile__ in the cpuid macro, since we don't depend on
> any effect of cpuid here.
>
> A \n is missing between processors.
>
> It detects too many processors on my machine: 16 instead of 8:
>
> i 00000000 a 0000000d b 756e6547 c 6c65746e d 49656e69
> i 00000001 a 000206a7 b 05100800 c 1fbae3ff d bfebfbff
> i 00000002 a 76035a01 b 00f0b2ff c 00000000 d 00ca0000
> i 00000003 a 00000000 b 00000000 c 00000000 d 00000000
> i 00000004 a 00000000 b 00000000 c 00000000 d 00000000
> i 00000005 a 00000040 b 00000040 c 00000003 d 00021120
> i 00000006 a 00000077 b 00000002 c 00000009 d 00000000
> i 00000007 a 00000000 b 00000000 c 00000000 d 00000000
> i 00000008 a 00000000 b 00000000 c 00000000 d 00000000
> i 00000009 a 00000000 b 00000000 c 00000000 d 00000000
> i 0000000a a 07300403 b 00000000 c 00000000 d 00000603
> i 0000000b a 00000000 b 00000000 c 000000e3 d 00000005
> i 0000000c a 00000000 b 00000000 c 00000000 d 00000000
> i 0000000d a 00000000 b 00000000 c 00000000 d 00000000
> a 80000008 b 00000000 c 00000000 d 00000000
> i 80000000 a 80000008 b 00000000 c 00000000 d 00000000
> i 80000001 a 00000000 b 00000000 c 00000001 d 28100800
> i 80000002 a 20202020 b 6e492020 c 286c6574 d 43202952
> i 80000003 a 2865726f b 20294d54 c 322d3769 d 51303237
> i 80000004 a 5043204d b 20402055 c 30322e32 d 007a4847
> i 80000005 a 00000000 b 00000000 c 00000000 d 00000000
> i 80000006 a 00000000 b 00000000 c 01006040 d 00000000
> i 80000007 a 00000000 b 00000000 c 00000000 d 00000100
> i 80000008 a 00003024 b 00000000 c 00000000 d 00000000
> Intel
> 2093
> processor       : 0
> vendor_id       : GenuineIntel
> model name      :       Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz
> core id         : 0
> cpuid-level     : 13
>
> processor       : 1
> vendor_id       : GenuineIntel
> model name      :       Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz
> core id         : 1
> cpuid-level     : 13
> processor       : 2
> vendor_id       : GenuineIntel
> model name      :       Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz
> core id         : 2
>
> etc. up to 15, while on Linux:
>
> processor       : 0
> physical id     : 0
> siblings        : 8
> core id         : 0
> cpu cores       : 4
> apicid          : 0
>
> processor       : 1
> physical id     : 0
> siblings        : 8
> core id         : 1
> cpu cores       : 4
> apicid          : 2
>
> processor       : 2
> physical id     : 0
> siblings        : 8
> core id         : 2
> cpu cores       : 4
> apicid          : 4
>
> processor       : 3
> physical id     : 0
> siblings        : 8
> core id         : 3
> cpu cores       : 4
> apicid          : 6
>
> processor       : 4
> physical id     : 0
> siblings        : 8
> core id         : 0
> cpu cores       : 4
> apicid          : 1
>
> processor       : 5
> physical id     : 0
> siblings        : 8
> core id         : 1
> cpu cores       : 4
> apicid          : 3
>
> processor       : 6
> physical id     : 0
> siblings        : 8
> core id         : 2
> cpu cores       : 4
> apicid          : 5
>
> processor       : 7
> physical id     : 0
> siblings        : 8
> core id         : 3
> cpu cores       : 4
> apicid          : 7
>
> That being said, since GNU Mach only supports one processor, I'd rather
> show only one processor in /proc/cpuinfo, because on Linux, cpuinfo
> only shows the running processors, and thus some tools would infer from
> /proc/cpuinfo that there are more than just 1 active processor.
>
> Samuel

cpuinfo.c
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cpuinfo.h
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patch
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