# 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:

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

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