The second example says "First allocate 1GiB, free it, then spawn a process which does the same but with 2GiB." In the code it seems it is the parent process

The second example says "First allocate 1GiB, free it, then spawn a process which does the same but with 2GiB." In the code it seems it is the parent process that does the second call too. if (pid != 0) { malloc_and_fill(1L << 31); } The result is not affected but the wording is not very clear I think.