[PATCH 13 of 16] simplify oom heuristics

[Andrea Arcangeli <andrea@suse.de>]

# HG changeset patch
# User Andrea Arcangeli <andrea@suse.de>
# Date 1181332962 -7200
# Node ID dfac333eb29032dab87dd2c46f71a22037a6dc4a
# Parent  db4c0ce6754d7838713eda1851aef43c2fb52fca
simplify oom heuristics

Over time somebody had the good idea to remove the rcvd_sigterm points,
this removes more of them. The selected task should be the one that if
we don't kill, it will turn the system oom again sooner than later.
These informations tell us nothing about which task is best to kill so
they should be removed.

Signed-off-by: Andrea Arcangeli <andrea@suse.de>

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -52,7 +52,7 @@ static unsigned long last_tif_memdie_jif
 
 unsigned long badness(struct task_struct *p, unsigned long uptime)
 {
-	unsigned long points, cpu_time, run_time, s;
+	unsigned long points;
 	struct mm_struct *mm;
 	struct task_struct *child;
 
@@ -93,26 +93,6 @@ unsigned long badness(struct task_struct
 			points += child->mm->total_vm/2 + 1;
 		task_unlock(child);
 	}
-
-	/*
-	 * CPU time is in tens of seconds and run time is in thousands
-         * of seconds. There is no particular reason for this other than
-         * that it turned out to work very well in practice.
-	 */
-	cpu_time = (cputime_to_jiffies(p->utime) + cputime_to_jiffies(p->stime))
-		>> (SHIFT_HZ + 3);
-
-	if (uptime >= p->start_time.tv_sec)
-		run_time = (uptime - p->start_time.tv_sec) >> 10;
-	else
-		run_time = 0;
-
-	s = int_sqrt(cpu_time);
-	if (s)
-		points /= s;
-	s = int_sqrt(int_sqrt(run_time));
-	if (s)
-		points /= s;
 
 	/*
 	 * Niced processes are most likely less important, so double

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