Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

From: Ferris McCormick (fmccor_at_[hidden])
Date: 2005-09-26 09:59:21

On Fri, 2005-09-16 at 11:35 -0500, Brian Barrett wrote:
> On Sep 16, 2005, at 8:44 AM, Ferris McCormick wrote:
> > ==========================================
> > fmccor_at_polylepis util [235]% ./opal_timer
> > --> frequency: 900000000
> > --> cycle count
> > Slept approximately 903151189 cycles, or 1003501 us
> > --> usecs
> > Slept approximately 18446744073289684648 us
> > ==========================================
> That last value means that I'm munging the upper 32 bits of the tick
> register (it's 64 bits long). So we're not quite there yet, but
> getting closer. I should be able to get to that today.
> The other problem is very odd. Since you're compiling in 32bit mode,
> I'd expect us to see it on our PowerPC machines, but I haven't run into
> that one yet. I'll try to compile without debugging and see what I can
> see.
> Brian
Here's a little more information on the SegFault when trying
OBJ_DESTRUCT(&verbose); in opal/util/optput.c:
First of all, verbose is of type opal_output_stream_t, and this is not
an opal_object_t, so OBJ_DESTRUCT is calling opal_obj_run_destructors
with an object of the wrong type (although ompi might be forcing storage
allocation so that this call should work; I haven't worked it out).

Second, on my system at least, when OBJ_DESTRUCT(&verbose) gets called,
verbose looks like this (I have a debug fprintf to try to look at a bit
of the verbose structure. The corresponding fprintf I put after
OBJ_CONSTRUCT(&verbose, opal_output_stream_t); is fine.)
Program received signal SIGSEGV, Segmentation fault.
0x7014f7d4 in opal_output_close (output_id=1883966264) at output.c:287
287 fprintf(stderr,"Destroying verbose, depth=%d
Current language: auto; currently c
(gdb) print verbose
$1 = {super = {obj_class = 0x0, obj_reference_count = 1},
lds_is_debugging = false,
lds_verbose_level = 0, lds_want_syslog = false, lds_syslog_priority =
lds_syslog_ident = 0x0, lds_prefix = 0x0, lds_want_stdout = false,
lds_want_stderr = true,
lds_want_file = false, lds_want_file_append = false, lds_file_suffix =
so that verbose.super.obj_class has been set to null, and no matter how
it is supposed to work, the opal_obj_run_destructors loop:
  cls = object->obj_class;
  for(i=0; i < cls->cls_depth;i++) { ...
is going to be working on garbage, because nothing in verbose has a
useful obj_class element.

Hope this helps,

Ferris McCormick (P44646, MI) <fmccor_at_[hidden]>
Developer, Gentoo Linux (Sparc, Devrel)