problems with shared memory

[somshekar kadam]

 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
<wolfgang.grandegger at bluewin.ch> 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:
>
> >I've got Linux 2.4.16 running on a custom MPC8260
> board.
> >
> >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
> >in the kernel to pop depending on what options I've
> compiled into the
> >kernel.  I believe I've got some memory corruption
> going on.  When I
> >poke around with a hardware debugger I see values
> in kernel structures
> >which clearly aren't right.
> >
> >Any known problems with shared memory in the 2.4.16
> kernel on the MPC8260?
> >
> >This should be easy enough for someone to try to
> reproduce.
> >
> >=== 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);
> >
> >   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
> >awozniak at comdev.cc      805 Aerovista Place, San
> Luis Obispo, CA 93401
> >                        http://www.comdev.cc
> >                        Voice: (805) 544-1089
> Fax: (805) 544-2055
> >
> >
> >
>
>
>


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