Subject: Re: kernel msgbuf size
To: Andrew Brown <codewarrior@daemon.org>
From: Eduardo E. Horvath <eeh@one-o.com>
List: current-users
Date: 07/08/1997 09:27:10
On Mon, 7 Jul 1997, Andrew Brown wrote:
> what am i gonna break if i raise the size of the (my) msgbuf from
>
> #define MSG_BSIZE (4096 - 3 * sizeof(long))
>
> to something much larger. say...
>
> #define MSG_BSIZE (16384 - 3 * sizeof(long))
>
I have always beleived that MSG_BSIZE should be:
#define MSG_BSIZE (NBPG - 3 * sizeof(long))
I did this to my own tree many moons ago when the Amiga port switched from
4K to 8K pages (or was it the other way around? I forget.) I felt is
was a bit silly to allocate an entire 8K page for the message buffer but
then only use 1/2 of it.
It might be a good idea to make this a tuneable, but then there's the
problem with syslog and debuggers. Of course, you could waste a whole
4 more bytes and embed the size in the message buf structure....
=========================================================================
Eduardo Horvath eeh@btr.com
"Cliffs are for climbing. That's why God invented grappling hooks."
- Benton Frasier