Martin Albrecht wrote:
> Hi there,
>
> in the thread
>
> http://is.gd/4EMT8
>
> David and I agreed that M4RI should have a better, more robust and cross-
> platform mechanism to check for cache sizes.
>
> Thus I wrote a little C program to check for the cache size using timings of
> random-ish memory access.
>
> The program is available at:
>
> http://sage.math.washington.edu/home/malb/cache.c
>
> On my Core 2 Duo and on my Opteron (both running Linux 64-bit) it does report
> correct sizes. So far so good. On sage.math it reports L3 cache size instead
> of L2 but I guess that this is probably what we want anyway (well, L2 is 3MB
> which I don't check explicitly since I only check powers of two)
>
> I'd appreciate if those people on this list who have different hardware or
> software (OSX, Solaris, PPC, Sparc) could compile the program and report back
> whether the program reports correct sizes for them. To compile and run:
>
> gcc -std=c99 -O3 cache.c -o cache
> ./cache
>
> Cheers,
> Martin
>
>
I get weird results. I'm running Ubuntu 9.10.
$ gcc -std=c99 -O3 cache.c -o cache
cache.c: In function ‘main’:
cache.c:76: warning: format ‘%5d’ expects type ‘int’, but argument 2 has
type ‘long long unsigned int’
cache.c:87: warning: format ‘%d’ expects type ‘int’, but argument 2 has
type ‘long long unsigned int’
$ ./cache
8 0.000 -0.000
16
-8398463032953819536247336566031312991144079686051738304471966669039044131696226829379239029189847822086924494434323213752880341006350643627443839933893593534174306352771682597911067433298676376261656732063193520999181558401504619215338835013847309758315074656817756377927909581189663689154228128221440770048.000
-0.000
32 673471.000
-3546708087032368915955808166786170270153026440174447921259530679463188870447462099420451834016308396836126150224828394415502900934890561646473632855796733445481167402961993728.000
64 -0.000 -0.000
128
4386232069291721889735509541787637405807919755643134523327764910072414863665047313350542797343329420530563038576640.000
-131931357829183911968937855162012273802567551268602401425480743944102328226184323665656750385578041448613881286965296761573714968002627576812191582953966300077162000745070667267722237290924429795183392756633890191020165687148544.000
256
2503611569399713855148608481271822535763266252234012757033381013768554066869594219726533588919968767093313447505134978978474018959540909750304742356025344.000
0.000
512
-93513432565550484438510715236443564573168515160919337181144690754754409573595642526779416692371271480790466936380617521548537175041417200460428583068428213762462397618732109092377183716006779661881573872191010623315024635533857877198920472330240.000
109512008301100481456024620353895874896748658409297314738534991754995542402778231387856941088234651429430984684839286860351126468724493479007598054415069698184269625285111917788286141298270190614651643613592088146877404825369138327564677283840.000
1024
191923198570832563990049271932142779609268025218941094751283485868219108703821277327345056713150758453463655966104481796286077182297588162420153411825539126913530793619420610560.000
-0.000
2048
-162819309274730042766000184290649529434208323906712420196011285131981290758643043996799018046221916953409758232126514849898367534701337185894069848408317327483176591020179941839072175320626228084914781022751672579028102891120970858350694388577584807936.000
0.000
4096
6061668001092683411032294693775044937673929957504593420229948438731788660315972745407394440239201644116169112554099867054939524888927116741546820718534066176.000
0.000
8192 0.000
21970836088519600003755032265160876833646536789476184571945655609415528972935079381217218300374409983567265039541677716406272.000
16384 -0.000 -0.000
32768
-10221624189657929071353503775365828355510148917915204126905015284741814585821516455281469397846102653544498988652817857816999026388231538822876858028074801569503027819935375026494300405462700053083024835388132270839469977292882849872393028896278572915908385742096618389241856.000
-0.000
65536 -0.000 0.000
8 512
$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 3.20GHz
stepping : 9
cpu MHz : 3192.654
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat
pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips : 6385.30
clflush size : 64
power management:
processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 3.20GHz
stepping : 9
cpu MHz : 3192.654
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 1
initial apicid : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat
pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips : 6384.74
clflush size : 64
power management:
$ gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
4.4.1-4ubuntu8' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--enable-shared --enable-multiarch --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4
--program-suffix=-4.4 --enable-nls --enable-clocale=gnu
--enable-libstdcxx-debug --enable-objc-gc --enable-targets=all
--disable-werror --with-arch-32=i486 --with-tune=generic
--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu
--target=i486-linux-gnu
Thread model: posix
gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu8)
$ uname -a
Linux littleone 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:04:26 UTC
2009 i686 GNU/Linux
--
Jason Grout
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send an email to sage-devel@googlegroups.com
To unsubscribe from this group, send an email to
sage-devel-unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sage-devel
URL: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---
