linux-2.6-540-oom-kill.patch

Index: linux-2.6.27.y/init/Kconfig
===================================================================
--- linux-2.6.27.y.orig/init/Kconfig
+++ linux-2.6.27.y/init/Kconfig
@@ -306,6 +306,23 @@ config CGROUP_DEVICE
 	  Provides a cgroup implementing whitelists for devices which
 	  a process in the cgroup can mknod or open.
 
+config OOM_PANIC
+	bool "OOM Panic"
+	default y
+	---help---
+	  This option enables panic() to be called when a system is out of
+	  memory. This feature along with /proc/sys/kernel/panic allows a
+	  different behavior on out-of-memory conditions when the standard
+	  behavior (killing processes in an attempt to recover) does not
+	  make sense.
+
+	  If unsure, say N.
+
+config OOM_KILL
+	bool
+	depends on !OOM_PANIC
+	default y
+
 config CPUSETS
 	bool "Cpuset support"
 	depends on SMP && CGROUPS
Index: linux-2.6.27.y/mm/oom_kill.c
===================================================================
--- linux-2.6.27.y.orig/mm/oom_kill.c
+++ linux-2.6.27.y/mm/oom_kill.c
@@ -177,6 +177,11 @@ unsigned long badness(struct task_struct
 	return points;
 }
 
+#if defined(CONFIG_OOM_PANIC) && defined(CONFIG_OOM_KILLER)
+#warning Only define OOM_PANIC or OOM_KILLER; not both
+#endif
+
+#ifdef CONFIG_OOM_KILLER
 /*
  * Determine the type of allocation constraint.
  */
@@ -454,6 +459,7 @@ out:
 	read_unlock(&tasklist_lock);
 	cgroup_unlock();
 }
+
 #endif
 
 static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
@@ -519,6 +525,7 @@ void clear_zonelist_oom(struct zonelist 
 	}
 	spin_unlock(&zone_scan_mutex);
 }
+EXPORT_SYMBOL_GPL(clear_zonelist_oom);
 
 /**
  * out_of_memory - kill the "best" process when we run out of memory
@@ -602,3 +609,47 @@ out:
 	if (!test_thread_flag(TIF_MEMDIE))
 		schedule_timeout_uninterruptible(1);
 }
+#endif /* CONFIG_OOM_KILLER */
+
+#ifdef CONFIG_OOM_PANIC
+/**
+ * out_of_memory - panic if the system out of memory?
+ */
+void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
+{
+	/*
+	 * oom_lock protects out_of_memory()'s static variables.
+	 * It's a global lock; this is not performance-critical.
+	 */
+	static spinlock_t oom_lock = SPIN_LOCK_UNLOCKED;
+	static unsigned long count;
+
+	spin_lock(&oom_lock);
+
+	/*
+	 * If we have gotten only a few failures,
+	 * we're not really oom. 
+	 */
+	if (++count >= 10) {
+		/*
+		 * Ok, really out of memory. Panic.
+		 */
+
+		printk("oom-killer: gfp_mask=0x%x\n", gfp_mask);
+		show_free_areas();
+
+		panic("Out Of Memory");
+	}
+	spin_unlock(&oom_lock);
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
+{
+	cgroup_lock();
+	panic("Memory cgroup out Of Memory");
+	cgroup_unlock();
+}
+
+#endif
+#endif /*  CONFIG_OOM_PANIC */
Index: linux-2.6.27.y/mm/oom_panic.c
===================================================================
--- /dev/null
+++ linux-2.6.27.y/mm/oom_panic.c
@@ -0,0 +1,51 @@
+/* 
+ * Just panic() instead of the default behavior of selecting processes
+ * for death.
+ *
+ * Based on
+ * Modular OOM handlers for 2.6.4 (C) 2003,2004 Tvrtko A. Ursulin
+ * and
+ * linux/mm/oom_kill.c (C) 1998,2000 Rik van Riel.
+ *
+ * Mark Huang <mlhuang@cs.princeton.edu>
+ *
+ * $Id: oom_panic.c,v 1.1 2004/10/01 17:54:48 mlhuang Exp $
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/swap.h>
+
+/**
+ * out_of_memory - is the system out of memory?
+ */
+void out_of_memory(int gfp_mask)
+{
+	/*
+	 * oom_lock protects out_of_memory()'s static variables.
+	 * It's a global lock; this is not performance-critical.
+	 */
+	static spinlock_t oom_lock = SPIN_LOCK_UNLOCKED;
+	static unsigned long count;
+
+	spin_lock(&oom_lock);
+
+	/*
+	 * If we have gotten only a few failures,
+	 * we're not really oom. 
+	 */
+	if (++count < 10)
+		goto out_unlock;
+
+	/*
+	 * Ok, really out of memory. Panic.
+	 */
+
+	printk("oom-killer: gfp_mask=0x%x\n", gfp_mask);
+	show_free_areas();
+
+	panic("Out Of Memory");
+
+out_unlock:
+	spin_unlock(&oom_lock);
+}
Index: linux-2.6.27.y/mm/page_alloc.c
===================================================================
--- linux-2.6.27.y.orig/mm/page_alloc.c
+++ linux-2.6.27.y/mm/page_alloc.c
@@ -1588,11 +1588,12 @@ nofail_alloc:
 		if (page)
 			goto got_pg;
 	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
+#ifdef CONFIG_OOM_KILLER
 		if (!try_set_zone_oom(zonelist, gfp_mask)) {
 			schedule_timeout_uninterruptible(1);
 			goto restart;
 		}
-
+#endif
 		/*
 		 * Go through the zonelist yet one more time, keep
 		 * very high watermark here, this is only to catch
@@ -1603,18 +1604,24 @@ nofail_alloc:
 			order, zonelist, high_zoneidx,
 			ALLOC_WMARK_HIGH|ALLOC_CPUSET);
 		if (page) {
+#ifdef CONFIG_OOM_KILLER
 			clear_zonelist_oom(zonelist, gfp_mask);
+#endif
 			goto got_pg;
 		}
 
 		/* The OOM killer will not help higher order allocs so fail */
 		if (order > PAGE_ALLOC_COSTLY_ORDER) {
+#ifdef CONFIG_OOM_KILLER
 			clear_zonelist_oom(zonelist, gfp_mask);
+#endif
 			goto nopage;
 		}
 
 		out_of_memory(zonelist, gfp_mask, order);
+#ifdef CONFIG_OOM_KILLER
 		clear_zonelist_oom(zonelist, gfp_mask);
+#endif
 		goto restart;
 	}