使用OpenMPI v2，当我使用-host运行测试程序时，它可以运行。我的意思是，该过程跨越我指定的主机。但是，当我指定-hostfile时，它不起作用!!
mahmood@cluster:mpitest$ /share/apps/computer/openmpi-2.0.1/bin/mpirun -host compute-0-0,cluster -np 2 a.out
****************************************************************************
* hwloc 1.11.2 has encountered what looks like an error from the operating system.
*
* Package (P#1 cpuset 0xffff0000) intersects with NUMANode (P#1 cpuset 0xff00ffff) without inclusion!
* Error occurred in topology.c line 1048
*
* The following FAQ entry in the hwloc documentation may help:
* What should I do when hwloc reports "operating system" warnings?
* Otherwise please report this error message to the hwloc user's mailing list,
* along with the output+tarball generated by the hwloc-gather-topology script.
****************************************************************************
Hello world from processor cluster.hpc.org, rank 1 out of 2 processors
Hello world from processor compute-0-0.local, rank 0 out of 2 processors
mahmood@cluster:mpitest$ cat hosts
cluster
compute-0-0
mahmood@cluster:mpitest$ /share/apps/computer/openmpi-2.0.1/bin/mpirun -hostfile hosts -np 2 a.out
****************************************************************************
* hwloc 1.11.2 has encountered what looks like an error from the operating system.
*
* Package (P#1 cpuset 0xffff0000) intersects with NUMANode (P#1 cpuset 0xff00ffff) without inclusion!
* Error occurred in topology.c line 1048
*
* The following FAQ entry in the hwloc documentation may help:
* What should I do when hwloc reports "operating system" warnings?
* Otherwise please report this error message to the hwloc user's mailing list,
* along with the output+tarball generated by the hwloc-gather-topology script.
****************************************************************************
Hello world from processor cluster.hpc.org, rank 0 out of 2 processors
Hello world from processor cluster.hpc.org, rank 1 out of 2 processors
那么问题是什么？如何解决？
答案 0 :(得分：2)
-host参数中列出的主机各提供一个插槽，因此-host A,B表示主机A上的一个插槽和主机B上的一个插槽。
要强制mpiexec为每个节点启动 N 进程，请使用以下选项
--map-by ppr:N:node
在您的情况下，对于每个节点一个进程，它应该是--map-by ppr:1:node。或者，您可以通过将主机文件修改为如下所示将每个主机的插槽数限制为一个：
cluster slots=1 max_slots=1
compute-0-0 slots=1 max_slots=1
（如果没有提供，slots=1应该是默认值...）