---
# System prepended metadata

title: Regular Meeting (2020.8.23)
tags: [Regular Meeting, DeWei]

---

# Regular Meeting (2020.8.23)

* Problem last week: order of parallel make 
* Gannt: 
  * https://hackmd.io/@BelleII-CDC-Trig-NTU-DeWei/r1PQ4WtJY

## Order of parallel make

### Problems

`target: prerequisite-1 prerequisite-2 ` has order `1 -> 2`, but when I run make *parallel* (`make -j <n-threads>`), 


while using multi-core CPU for comiplation (with -j), this order is **not always** followed. It could be `1 -> 2`, or **maybe** `2 -> 1`.


### Solution: `|` symbol: Order-only prerequisites

usage: 

``` makefile
target: prerequisite-1 prerequisite-2 | order-only-prerequisite-1 order-only-prerequisite-2 
  ${make} -C dir
```



###### tags: `Regular Meeting` `DeWei`