adding on the the sibling, what argument to clone allows me to set the fds of the child? AFAIK, you either share the FD table with the parent, or get a copy of it. If the parent has 1 million FDs open and the child doesn't want most of those, dealing with that has real costs. Many applications that tend to have large numbers of FDs and also fork/exec will mitigate the cost by spawning a process during startup that they can then use to spawn processes during runtime without doing it from the main process; this is a nice mitigation, but it shows a missing interface.
adding on the the sibling, what argument to clone allows me to set the fds of the child? AFAIK, you either share the FD table with the parent, or get a copy of it. If the parent has 1 million FDs open and the child doesn't want most of those, dealing with that has real costs. Many applications that tend to have large numbers of FDs and also fork/exec will mitigate the cost by spawning a process during startup that they can then use to spawn processes during runtime without doing it from the main process; this is a nice mitigation, but it shows a missing interface.