Hello all,
as raised on todays telcon:
WHAT: Obeying or lowering default priority of PML/CM.
WHY: Not obvious why MTLs are not used for Portals/MX
WHEN: On trunk, Tuesday afternoon 18 Aug 2009
On 1.3 by CMR on 25 Aug 2009
TIMEOUT: Tuesday telconf, 18 Aug 2009
---------------------------------------------------------------
When compiling on systems with MX or Portals, we offer MTLs and BTLs.
If MTLs are used, the PML/CM is loaded as well as the PML/OB1.
The current default priority for them is:
@jaguar13:~> ompi_info --param pml all | grep priority
MCA pml: parameter "pml_cm_priority" (current value: <30>, ...)
MCA pml: parameter "pml_ob1_priority" (current value: <20>, ...)
Now in pml_cm_component.c:113 the priority however is changed:
} else if(strcmp(ompi_mtl_base_selected_component->
mtl_version.mca_component_name, "psm") != 0) {
/* if mtl is not PSM then back down priority, and require user to*/
/* specify pml cm directly if that is what they want priority */
/* of 1 is sufficient in that case as it is the only pml that */
/* will be considered */
*priority = 1;
}
which is kind of "unexpected" to the user ;-)
This moved into trunk in r13576. I had a off-list mail with Galen on the
reasoning of this part of the patch, now I would like to address the
community.
Question 1: Is favoring OB1 over CM required for any MTL (MX, Portals, PSM)?
Question 2: If it is, I would like to reflect this in the default priorities,
aka have CM have a priority lower than OB1 and in the case of PSM raising it.
I'd like to raise any issues until next week's telcon.
Actions Taken:
If no objections are raised for Question 1, I would like to remove the
lowering of the CM's priority and have it always favoured over OB1.
If there are issues with that, I would like to patch such that:
svn diff pml_cm_component.c
Index: pml_cm_component.c
===================================================================
--- pml_cm_component.c (revision 21786)
+++ pml_cm_component.c (working copy)
@@ -106,7 +106,7 @@
"CM PML selection priority",
false,
false,
- 30,
+ 10,
&ompi_pml_cm.default_priority);
return OMPI_SUCCESS;
@@ -139,12 +139,12 @@
if (OMPI_SUCCESS != ret) {
*priority = -1;
return NULL;
- } else if(strcmp(ompi_mtl_base_selected_component-
>mtl_version.mca_component_name, "psm") != 0) {
+ } else if(strcmp(ompi_mtl_base_selected_component-
>mtl_version.mca_component_name, "psm") == 0) {
- /* if mtl is not PSM then back down priority, and require the user
to */
- /* specify pml cm directly if that is what they want priority */
- /* of 1 is sufficient in that case as it is the only pml that */
- /* will be considered */
- *priority = 1;
+ *priority = 30;
}
/* modulo updating the comment */
Best regards,
Rainer
--
------------------------------------------------------------------------
Rainer Keller, PhD Tel: +1 (865) 241-6293
Oak Ridge National Lab Fax: +1 (865) 241-4811
PO Box 2008 MS 6164 Email: kel...@ornl.gov
Oak Ridge, TN 37831-2008 AIM/Skype: rusraink
