/*
 *  linux/mm/oom_kill.c
 * 
 *  Copyright (C)  1998,2000  Rik van Riel
 *	Thanks go out to Claus Fischer for some serious inspiration and
 *	for goading me into coding this file...
 *
 *  The routines in this file are used to kill a process when
 *  we're seriously out of memory. This gets called from kswapd()
 *  in linux/mm/vmscan.c when we really run out of memory.
 *
 *  Since we won't call these routines often (on a well-configured
 *  machine) this file will double as a 'coding guide' and a signpost
 *  for newbie kernel hackers. It features several pointers to major
 *  kernel subsystems and hints as to where to find out what things do.
 */ 

 * The formula used is relatively simple and documented inline in the
 * function. The main rationale is that we want to select a good task
 * to kill when we run out of memory.
 *
 * Good in this context means that:
 *  1 ) we lose the minimum amount of work done
 *  2 ) we recover a large amount of memory
 *  3 ) we don't kill anything innocent of eating tons of memory
 *  4 ) we want to kill the minimum amount of processes (one)
 *  5 ) we try to kill the process the user expects us to kill, this
 *    algorithm has been meticulously tuned to meet the priniciple
 *    of least surprise ... (be careful when you change it)