From 924bc10ceb87b46dda9645e6286d0fd1d2cd766c Mon Sep 17 00:00:00 2001 From: Eugene Loh Date: Sat, 6 Feb 2010 06:22:29 +0000 Subject: [PATCH] Add description of the sequential mapper (-mca rmaps seq) to the mpirun man page. This commit was SVN r22567. --- orte/tools/orterun/orterun.1in | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/orte/tools/orterun/orterun.1in b/orte/tools/orterun/orterun.1in index 7af6aff695..a086f485d4 100644 --- a/orte/tools/orterun/orterun.1in +++ b/orte/tools/orterun/orterun.1in @@ -680,12 +680,15 @@ will launch ranks 0-3 on node aa and ranks 4-5 on node bb. The remaining slots in the hostfile will not be used since the \fI-np\fP option indicated that only 6 processes should be launched. . -.SS Mapping Processes to Nodes +.SS Mapping Processes to Nodes: Using Policies . The examples above illustrate the default mapping of process ranks to nodes. This mapping can also be controlled with various -\fImpirun\fP options. Here, we consider the same hostfile as -above with \fI-np\fP 6 again: +\fImpirun\fP options that describe mapping policies. +. +. +.PP +Consider the same hostfile as above, again with \fI-np\fP 6: . node aa node bb node cc @@ -770,6 +773,27 @@ mpirun -H aa -np 1 hostname : -H bb,cc -np 2 uptime will launch process 0 running \fIhostname\fP on node aa and processes 1 and 2 each running \fIuptime\fP on nodes bb and cc, respectively. . +.SS Mapping Processes to Nodes: Using Arbitrary Mappings +. +The mapping of process ranks to nodes can be prescribed not just +with general policies but also, if necessary, using arbitrary mappings +that cannot be described by a simple policy. One can use the "sequential +mapper," which reads the hostfile line by line, assigning processes +to nodes in whatever order the hostfile specifies. Use the +\fI-mca rmaps seq\fP option. For example, using the same hostfile +as before +. +.TP 4 +mpirun -hostfile myhostfile ./a.out +will launch three processes, on ranks aa, bb, and cc, respectively. +The slot counts don't matter; one process is launched per line on +whatever node is listed on the line. +. +.PP +Another way to specify arbitrary mappings is with a rank file, which +gives you detailed control over process binding as well. Rank files +are discussed below. +. .SS Process Binding . Processes may be bound to specific resources on a node. This can