Re: Linux exec_pagesize

Bob Bachman wrote:

> From: Bob Bachman <bobach@...>
>
> Arne,
>
> Does the change in EXEC_PAGESIZE have to be done before compiling the
> kernel or can
> it be done after compiling?

The kernel???? Of course, the kernel MAKES this decision based on the
CPU it is booting up on (as I understand things). So, it is dynamically
decided at boot time. EMC doesn't poke around and find out what it is
set to, just assumes Pentium normal of 4096 (I think). So, you have
to override EMC's incorrect assumption, in the VERY few places this
makes a difference. That is where EMC's components allocate chunks
of available shared memory at the top of the physical system memory
that has been left unused when Linux booted.

(now, looking at that 2nd thing to do that Arne notes below, maybe this
is actually fixing a bug in the Linux include files, in that the Linux install and
kernel build procedure doesn't leave allowance for something in the
include files needing to be changed dynamically at boot time.
Hmmm, some meat for Linus himself to chew on!

>
> Bob
>
> >I used a 486, and I recall that someone said they wanted
> >to set up a 486 in their workshop. There is some files that needs
> >to be modified to get it working with the RT kernel, because it uses
> >shared memory a little differently:
> >- in lilo.conf : append="mem=xxx" - set aside less than 1M
> >- in /usr/src/linux/include/asm-i386/param.h - change #define
> >EXEC_PAGESIZE 4096 to
> >
> >#define EXEC_PAGESIZE 1024
> >- then the good guys at NIST has done corrections in the
> >emc-06-Jul-1999.tgz
> >