Re: [PATCHES] update i386 spinlock for hyperthreading - Mailing list pgsql-hackers

Hi Manfred,

I'm using unixware 7 but couldn't compile your source with native cc, I
had to compile it with gcc.

here are the results:

Script started on Sat Dec 27 17:50:49 2003
/tmp 17:50:50: ./a.out
MOVETEST called by non-superuser, running with normal priority.
zerotest:    -1073736628 ticks;
zerotest:         -4372 ticks;
zerotest:           -52 ticks;
rep nop:           508 ticks;
rep nop:            88 ticks;
rep nop:            60 ticks;
nop:           256 ticks;
nop:           224 ticks;
nop:            92 ticks;
nop:            64 ticks;
nop:            12 ticks;
nop:             8 ticks;
nop:             0 ticks;
nop:            -4 ticks;
rep nop:            56 ticks;
rep nop:            44 ticks;
rep nop:            40 ticks;
zerotest:            -4 ticks;
rep nop:            24 ticks;
zerotest:            -4 ticks;
nop:             0 ticks;
zerotest:            -4 ticks;
nop:            -8 ticks;
zerotest:            -8 ticks;
rep nop:            32 ticks;
nop:           -16 ticks;
zerotest:            -4 ticks;
zerotest:            -4 ticks;
rep nop:            24 ticks;
zerotest:            -4 ticks;
nop:           -12 ticks;
^?
/tmp 17:53:34: exit

script done on Sat Dec 27 17:53:38 2003

Regards
On Sat, 27 Dec 2003, Manfred Spraul wrote:

> Date: Sat, 27 Dec 2003 12:22:45 +0100
> From: Manfred Spraul <manfred@colorfullife.com>
> To: ohp@pyrenet.fr
> Subject: Re: [PATCHES] update i386 spinlock for hyperthreading
>
> Hi Olivier,
>
> I have attached rep_nop.cpp. It's a simple C program (unfortunately
> filled with linux specific gccisms) that benchmarks the time for a
> single rep;nop instruction, compared to a normal nop and nothing at all.
>
> Which OS do you use? I can try to build an app for FreeBSD, and it
> should be possible to compile it under Windows with cygwin as well.
>
> Under Linux:
> $ gcc -O2 -o rep_nop rep_nop.cpp
> $ ./rep_nop
>
> Just run in for a few seconds and send back the output. Please add the
> mailing list back into the cc list.
> --
>     Manfred
>

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