From beb764ac03e52eba1a654afb4273fab1f9de3cff Mon Sep 17 00:00:00 2001

From: Kyle McMartin <kyle@mcmartin.ca>

Date: Mon, 29 Nov 2010 20:59:14 -0500

Subject: [PATCH] linux-2.6-debug-vm-would_have_oomkilled

---

 include/linux/oom.h |    1 +

 kernel/sysctl.c     |    7 +++++++

 mm/oom_kill.c       |    8 ++++++++

 3 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/include/linux/oom.h b/include/linux/oom.h

index 5e3aa83..79a27b4 100644

--- a/include/linux/oom.h

+++ b/include/linux/oom.h

@@ -72,5 +72,6 @@ extern struct task_struct *find_lock_task_mm(struct task_struct *p);

 extern int sysctl_oom_dump_tasks;

 extern int sysctl_oom_kill_allocating_task;

 extern int sysctl_panic_on_oom;

+extern int sysctl_would_have_oomkilled;

 #endif /* __KERNEL__*/

 #endif /* _INCLUDE_LINUX_OOM_H */

diff --git a/kernel/sysctl.c b/kernel/sysctl.c

index 5abfa15..a0fed6d 100644

--- a/kernel/sysctl.c

+++ b/kernel/sysctl.c

@@ -1000,6 +1000,13 @@ static struct ctl_table vm_table[] = {

 		.proc_handler	= proc_dointvec,

 	},

 	{

+		.procname	= "would_have_oomkilled",

+		.data		= &sysctl_would_have_oomkilled,

+		.maxlen		= sizeof(sysctl_would_have_oomkilled),

+		.mode		= 0644,

+		.proc_handler	= proc_dointvec,

+	},

+	{

 		.procname	= "overcommit_ratio",

 		.data		= &sysctl_overcommit_ratio,

 		.maxlen		= sizeof(sysctl_overcommit_ratio),

diff --git a/mm/oom_kill.c b/mm/oom_kill.c

index 7dcca55..281ac39 100644

--- a/mm/oom_kill.c

+++ b/mm/oom_kill.c

@@ -35,6 +35,7 @@

 int sysctl_panic_on_oom;

 int sysctl_oom_kill_allocating_task;

 int sysctl_oom_dump_tasks = 1;

+int sysctl_would_have_oomkilled;

 static DEFINE_SPINLOCK(zone_scan_lock);

 #ifdef CONFIG_NUMA

@@ -477,6 +478,13 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,

 	}

 	task_lock(p);

+	if (sysctl_would_have_oomkilled) {

+		printk(KERN_ERR "%s: would have killed process %d (%s), but continuing instead...\n",

+			__func__, task_pid_nr(p), p->comm);

+		task_unlock(p);

+		return 0;

+	}

+

 	pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n",

 		message, task_pid_nr(p), p->comm, points);

 	task_unlock(p);

-- 

1.7.3.2