我正在运行一个调用mpirun的可执行文件(我无权访问源代码)。我收到以下错误，如果请求的内核多于 CPU 上的可用内核，则常见错误：
There are not enough slots available in the system to satisfy the 12
slots that were requested by the application:
/Users/me/Library/app/executable
Either request fewer slots for your application, or make more slots
available for use.
A "slot" is the Open MPI term for an allocatable unit where we can
launch a process. The number of slots available are defined by the
environment in which Open MPI processes are run:
1. Hostfile, via "slots=N" clauses (N defaults to number of
processor cores if not provided)
2. The --host command line parameter, via a ":N" suffix on the
hostname (N defaults to 1 if not provided)
3. Resource manager (e.g., SLURM, PBS/Torque, LSF, etc.)
4. If none of a hostfile, the --host command line parameter, or an
RM is present, Open MPI defaults to the number of processor cores
In all the above cases, if you want Open MPI to default to the number
of hardware threads instead of the number of processor cores, use the
--use-hwthread-cpus option.
Alternatively, you can use the --oversubscribe option to ignore the
number of available slots when deciding the number of processes to
launch.
我的问题是我无法更改mpirun的命令行选项，例如使用--oversubscribe.相反，我需要更改 OpenMPI "看到"的默认内核数。(这将是一个简单的修复，否则在这种情况下)
是否有环境变量或我可以更新的东西来诱骗 openMPI 工作？
啊。我在/usr/local/etc/openmpi-default-hostfile(在Mac上)找到了默认的OpenMPI主机文件，并在末尾(在新行中)添加了该文件：
localhost slots=12
所以 OpenMPI 读取的默认slots计数为6，因为我的系统上有 6 个内核(错误仅发生在>6 个请求的 CPU 上)。但是我有 12 个线程，想满负荷使用 CPU。
这对我有用，因为我没有在命令行中运行mpirun。