The patch titled
support for panic at OOM
has been removed from the -mm tree. Its filename is
support-for-panic-at-oom.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: support for panic at OOM
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
This patch adds panic_on_oom sysctl under sys.vm.
When sysctl vm.panic_on_oom = 1, the kernel panics intead of killing rogue
processes. And if vm.panic_on_oom is 0 the kernel will do oom_kill() in
the same way as it does today. Of course, the default value is 0 and only
root can modifies it.
In general, oom_killer works well and kill rogue processes. So the whole
system can survive. But there are environments where panic is preferable
rather than kill some processes.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
Documentation/sysctl/vm.txt | 13 +++++++++++++
include/linux/sysctl.h | 1 +
kernel/sysctl.c | 9 +++++++++
mm/oom_kill.c | 3 +++
4 files changed, 26 insertions(+)
diff -puN Documentation/sysctl/vm.txt~support-for-panic-at-oom Documentation/sysctl/vm.txt
--- a/Documentation/sysctl/vm.txt~support-for-panic-at-oom
+++ a/Documentation/sysctl/vm.txt
@@ -29,6 +29,7 @@ Currently, these files are in /proc/sys/
- drop-caches
- zone_reclaim_mode
- zone_reclaim_interval
+- panic_on_oom
==============================================================
@@ -178,3 +179,15 @@ Time is set in seconds and set by defaul
Reduce the interval if undesired off node allocations occur. However, too
frequent scans will have a negative impact onoff node allocation performance.
+=============================================================
+
+panic_on_oom
+
+This enables or disables panic on out-of-memory feature. If this is set to 1,
+the kernel panics when out-of-memory happens. If this is set to 0, the kernel
+will kill some rogue process, called oom_killer. Usually, oom_killer can kill
+rogue processes and system will survive. If you want to panic the system
+rather than killing rogue processes, set this to 1.
+
+The default value is 0.
+
diff -puN include/linux/sysctl.h~support-for-panic-at-oom include/linux/sysctl.h
--- a/include/linux/sysctl.h~support-for-panic-at-oom
+++ a/include/linux/sysctl.h
@@ -186,6 +186,7 @@ enum
VM_PERCPU_PAGELIST_FRACTION=30,/* int: fraction of pages in each percpu_pagelist */
VM_ZONE_RECLAIM_MODE=31, /* reclaim local zone memory before going off node */
VM_ZONE_RECLAIM_INTERVAL=32, /* time period to wait after reclaim failure */
+ VM_PANIC_ON_OOM=33, /* panic at out-of-memory */
};
diff -puN kernel/sysctl.c~support-for-panic-at-oom kernel/sysctl.c
--- a/kernel/sysctl.c~support-for-panic-at-oom
+++ a/kernel/sysctl.c
@@ -59,6 +59,7 @@ extern int proc_nr_files(ctl_table *tabl
extern int C_A_D;
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
+extern int sysctl_panic_on_oom;
extern int max_threads;
extern int sysrq_enabled;
extern int core_uses_pid;
@@ -702,6 +703,14 @@ static ctl_table vm_table[] = {
.proc_handler = &proc_dointvec,
},
{
+ .ctl_name = VM_PANIC_ON_OOM,
+ .procname = "panic_on_oom",
+ .data = &sysctl_panic_on_oom,
+ .maxlen = sizeof(sysctl_panic_on_oom),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
.ctl_name = VM_OVERCOMMIT_RATIO,
.procname = "overcommit_ratio",
.data = &sysctl_overcommit_ratio,
diff -puN mm/oom_kill.c~support-for-panic-at-oom mm/oom_kill.c
--- a/mm/oom_kill.c~support-for-panic-at-oom
+++ a/mm/oom_kill.c
@@ -22,6 +22,7 @@
#include <linux/jiffies.h>
#include <linux/cpuset.h>
+int sysctl_panic_on_oom;
/* #define DEBUG */
/**
@@ -344,6 +345,8 @@ void out_of_memory(struct zonelist *zone
break;
case CONSTRAINT_NONE:
+ if (sysctl_panic_on_oom)
+ panic("out of memory. panic_on_oom is selected\n");
retry:
/*
* Rambo mode: Shoot down a process and hope it solves whatever
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
acpi-memory-hotplug-cannot-manage-_crs-with-plural-resoureces.patch
pgdat-allocation-for-new-node-add-generic-alloc-node_data.patch
pgdat-allocation-for-new-node-add-refresh-node_data.patch
pgdat-allocation-for-new-node-add-export-kswapd-start-func.patch
pgdat-allocation-for-new-node-add-export-kswapd-start-func-fix.patch
pgdat-allocation-for-new-node-add-call-pgdat-allocation.patch
register-hot-added-memory-to-iomem-resource.patch
catch-valid-mem-range-at-onlining-memory.patch
node-hotplug-register-cpu-remove-node-struct.patch
node-hotplug-register-cpu-remove-node-struct-alpha-fix.patch
remove-empty-node-at-boot-time.patch
namespaces-utsname-sysctl-hack-cleanup-2-fix.patch
reiser4-hardirq-include-fix.patch
genirq-rename-desc-handler-to-desc-chip-ia64-fix-2.patch
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