Subject: Re: i386 MP performance (generic.mp and generic almost same)
To: Cem Kayali <cemkayali@eticaret.com.tr>
From: Michael Lorenz <macallan@netbsd.org>
List: current-users
Date: 11/10/2007 22:44:54
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,

On Nov 10, 2007, at 21:06, Cem Kayali wrote:

>
> Hi,
>
> I would like to ask experiences of netbsd-current-users running
> multi-procesor kernel. I have core-duo notebook, and am using standart
> generic.mp kernel. dmesg shows i have cpu0 and cpu1.
>
> Tonight, i have compiled generic kernel, and noticed that there is  
> almost no
> performance difference... I mean,
>
> - Boot time is almost same (untill kde desktop just loaded)
> - KDE performance is almost same (windows startup etc)
> - Linux emulation software (Firefox,OO2) peformance (startup time)  
> is same.

All this depends more on disk performance than anything else. More or  
faster CPUs won't magically make your disk any faster.

> - More importantly, compiling a new kernel or compiling a software  
> through
> pkgsrc (from source) time is almost same.

As far as I know pkgsrc doesn't support parallel builds yet, so that  
will more or less run on one CPU. Then, when you built a kernel - did  
you actually do a parallel build? With -j <number_of_jobs> ? If not  
you won't see any benefit from the 2nd CPU.

> Well, i think i should somehow notice difference between generic  
> and generic.mp kernels...

You will, with programs that use multiple threads and are actually  
CPU-bound.

have fun
Michael
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (Darwin)

iQEVAwUBRzZ6t8pnzkX8Yg2nAQIDnAf+NdDE9TA+7FP4+5DoTtcUgkF2ZxAzJWL7
9YvGfc10uNH2piA0IyJ7PC1yar8ZgvuT0p9mxCaFLJGpM/NRzb4uBIgrpU7dEK0M
DOeDCrLPuzUVRTD+wElDAkV4Ob6MpGdYwghCDx4K90Gw7FpWp5DdhAzGMBYW5OD2
qqdMt3yXw1KBZhHZn3Fz022QdOOj3dzAPDNBKXqP6cP+bwog5Q0V4eyjzpALRDD/
SsUgqCAOKb+p9wv6e55FKjMJjjG3MZApEYt+wPqjqua6/0Zy1sbc+DZjgWHARziz
v7jO/42XlIQpHJFA6xzra1BRFzhvHov9sfRo9C/hkDtev3QxE8UALA==
=1ofY
-----END PGP SIGNATURE-----