[English words] pull; push

pull pull;
of course, it is not the same as the shit in Chinese. The pull in Chinese means to go down, and the shit in Chinese is very push shit down;
and the pull here means to pull closer.
For example: __pskb_pull_tail, the interpretation of this function is: advance tail of skb header, advance the distance of one skb header to the tail. The meaning is similar to pulling the rope, which is to draw the tail closer. The translation is to draw the tail closer to the distance of an skb header.