Re: problems with shared memory

 hi,

 i am having 8264 ,i wnat to know

to map my pci memory space and io space i will set the
bat registers using setbat function


but how to initialise ptes (page table entry)  does
any one haveany idea
or where it is in kernel let me know
i am not clear regarding this
thanks in advance
somshekar

--- Wolfgang Grandegger

[off-list ref] wrote: >

Hi Adam,

David Ashley has reported lately a bug in
arch/ppc/mm/ppc_mmu.c (see

http://lists.linuxppc.org/linuxppc-embedded/200202/msg00307.html),

which seems to be present in the linuxppc_2_4 tree
but not in the
linuxppc_2_4_devel tree.

Hope it helps,

Wolfgang.


Adam Wozniak wrote:

quoted

I've got Linux 2.4.16 running on a custom MPC8260

board.

quoted

when I do the program below in a tight loop
i.e.

while true
do
./foo 8675 1024
done

Things pop after about 20 iterations.  It'll choose

a different spot

quoted

in the kernel to pop depending on what options I've

compiled into the

quoted

kernel.  I believe I've got some memory corruption

going on.  When I

quoted

poke around with a hardware debugger I see values

in kernel structures

quoted

which clearly aren't right.

Any known problems with shared memory in the 2.4.16

kernel on the MPC8260?

quoted

This should be easy enough for someone to try to

reproduce.

quoted

=== begin foo.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/shm.h>

int main (int argc, char **argv)
{
  int j;
  char *q;
  int p;

  p = shmget(atoi(argv[1]),  atoi(argv[2]),

IPC_CREAT | 0666);

quoted

  q = shmat(p, NULL, 0);

  printf("at @ %p \n", q);

  {
     int i;
     for (i = 0; i < atoi(argv[2]); i++)
     {
        q[i]++;
     }
  }

  shmdt(q);
}
=== end foo.c

--
Adam Wozniak (KG6GZR)   COM DEV Broadband - Digital

and Software Systems

quoted

awozniak@comdev.cc      805 Aerovista Place, San

Luis Obispo, CA 93401

quoted

                       http://www.comdev.cc
                       Voice: (805) 544-1089

Fax: (805) 544-2055

quoted

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/