--- title: Atomic/Memory Registration/Send Request (羅君瑜) tags: Session one --- ## Atomic 當多個指令對同個記憶體進行修改時 ![](https://i.imgur.com/oAdi21A.png) ![](https://i.imgur.com/vlrMbBS.png) ![](https://i.imgur.com/qGSoIDb.png) ## Memory Registration ![](https://i.imgur.com/RjPyqpt.png) ![](https://i.imgur.com/sYAZObw.jpg) ![](https://i.imgur.com/fYtHsdB.png) ![](https://i.imgur.com/RuSakxi.png) ![](https://i.imgur.com/5qP4Ifi.jpg) ![](https://i.imgur.com/iB05aTo.png) ![](https://i.imgur.com/HBmsbaV.jpg) ![](https://i.imgur.com/mqPOQqc.jpg) ![](https://i.imgur.com/cmjWl2f.png) ## Send request ![](https://i.imgur.com/Dkiainu.png) ![](https://i.imgur.com/VTN3tGF.png) **一般情形** ![](https://i.imgur.com/N727EwL.png) **gather** 記憶體位置不連續的data可以傳送至一塊連續的記憶體位置 ![](https://i.imgur.com/Jy5XFjF.png) **scatter** 將原本記憶體位置連續的data傳送至不連續的記憶體位置 情形 : system A 要 Send data 給 system B ![](https://i.imgur.com/lRksYcH.png)