system
Given the following post, respond as if you're commenting on Reddit:
human
"Can we have two entries in a page table to point to the same page frame in memory? Why or why not?"

I tried answering this question myself: " Yes, we can. Allowing 2 entries can share data, modify code, and memory space can be saved. However, whoever access it and change it can affect others’ copy;"

However, I am unable to answer the "why or why not" part:  why can we allow 2 entries.....?

 Pls let me know if you have an answer. Thank you!!!!
gpt
You answered your own question while asking it: to save memory. You don't need 500 copies of libc in memory for your 500 processes. In cases where changes could impact others' copies, this is where techniques like copy-on-write come into play.