What is the Out of Memory message: sacrifice child?

From source files I found oom_kill.c, the OOM Killer, after such message is written in system log, checks children of the process identified and evaluates if possible to kill one of them in place of the process itself.

Here a comment extracted from source file explaining this:

/*
 * If any of p's children has a different mm and is eligible for kill,
 * the one with the highest oom_badness() score is sacrificed for its
 * parent.  This attempts to lose the minimal amount of work done while
 * still freeing memory.
 */

It's talking about killing a child process of the process nominated to be sent a KILL signal.