Newsgroups: comp.parallel.pvm
From: rajeshm@ee.pdx.edu (Rajesh S. Madukkarumukumana)
Subject: PVM multicasting and route policies ?
Keywords: pvm
Date: 22 May 1995 08:24:28 -0700
Message-ID: <3pqabc$12t@rafiki.ee.pdx.edu>


Hi,

	  The PVM3 user's maula says the current implementation of pvm_mcast() only
	  routes multicast messages through the pvmds. Does this mean that "direct"
	  route has no effect on multicast messages. Some measurements I made showed
	  "normal" route performing better than "direct" route between processes on
	  smae host and between different hosts over ethernet. Even though I can
	  reproduce the charachteristics, I am not sure whether this is correct.
	  Please email your suggestions to rajeshm@ee.pdx.edu. I am enclosing a
	  sample data set of measurements.

	  [on-host times are measured with all processes on same host]
	  [inter-host times are measured with one process per host]

			*-------------------------------------------------------------*
			|    MULTICAST  TIMINGS (uSecs)   (Message size = 4 bytes)    |
 *-------*------------------------------*------------------------------*
 | # of  |      on-host timings         |      inter-host timings      |
 ! rece- *--------------*---------------*--------------*----------*----*
 | ivers | Normal Route |  Direct Route | Normal Route | Direct Route  |
 *-------*--------------*---------------*--------------*---------------*
 |   1   |    2250      |     2441      |    2843      |    4364       |
 |   2   |    2320      |     2834      |    3870      |    4524       |
 |   3   |    2379      |     2926      |    4126      |    4602       |
 |   4   |    2446      |     2930      |    4855      |    5471       |
 |   5   |    2490      |     2947      |    5013      |    6228       |
 |   6   |    2501      |     3036      |    5945      |    8278       |
 |   7   |    2520      |     3057      |    6200      |    8640       |
 |   8   |    2537      |     3169      |    6911      |    9477       |
 |   9   |    2625      |     3506      |    7550      |   10624       |
 *-------*--------------*---------------*--------------*---------------*




	  Thanks

	  --Rajesh

	  [rajeshm@ee.pdx.edu]


