有没有人能解释一下lsf里slot、task、core、host等概念

zhangdeshuai

lsf的文档上的描述：

1. The following job asks for six slots and runs within single host. Each slot maps to one core. LSF tries to pack six cores as close as possible on single NUMA or socket. If the task distribution cannot be satisfied, the job can not be started.
   
2. 
   
3. bsub -n 6 –R "span[hosts=1] affinity[core(1):distribute=pack]" myjob
   

复制代码

看起来-n代表slots。但是查询bsub -n参数的解释：

1. bsub -n min_tasks[,max_tasks]
   
2. Description
   
3. The number of tasks is used to allocate a number of slots for the job. Usually, the number of slots assigned to a job will equal the number of tasks specified. For example, one task will be allocated with one slot. (Some slots/processors may be on the same multiprocessor host).
   
4. 
   
5. You can specify a minimum and maximum number of tasks. For example, this job requests a minimum of 4, but can launch up to 6 tasks:
   
6. 
   
7. bsub -n 4,6 a.out
   
8. 
   
9. The job can start if at least the minimum number of slots/processors is available for the minimum number of tasks specified. If you do not specify a maximum number of tasks, the number you specify represents the exact number of tasks to launch.
   

复制代码

“Some slots/processor”这里的描述看起来slots和processor的概念一致，那processor和core的区别是啥？我的理解是processor就是指的core。

还有-n指定task数量也有疑问。我的理解是bsub一条命令是1个task，怎么还会有指定task数量的操作？如果指的是提交的命令使用到的进程或者核心数量，那么应该通过“affinity[core(1):distribute=pack]”里的core数量配置就行，为什么还要-n？