📚 any good resources on memory overcommitment?

I am kinda intrested to know when does malloc actually give null because of lack of memory on linux.
its surprisingly non trivial... I asked on the c subreddit and got a few edge cases (if u set ulimit then u will be heled to that limit or if u ask for more memory than physically possible to alocate in 1 query)

but other than these 2 cases I havent really seen a good answer for when in a normal use of linux malloc would return null. seems like it usually overcommits but I am not sure if it allways does that. I believe that's not the case since that's a specific setting you can opt into.