[PATCH 1/3] PM: Disable OOM killer during system-wide power transitions

Rafael J. Wysocki
2009-05-01T22:27:30Z

From: Rafael J. Wysocki <rjw-KKrjLPT3xs0@public.gmane.org>

The OOM killer is not particularly useful during system-wide power
transitions, so do not use it if such a transition is in progress.

Signed-off-by: Rafael J. Wysocki <rjw-KKrjLPT3xs0@public.gmane.org>
---
include/linux/suspend.h | 4 ++++
kernel/power/disk.c | 13 ++++++++++++-
kernel/power/main.c | 13 +++++++++++++
kernel/power/power.h | 1 +
mm/page_alloc.c | 8 ++++++--
5 files changed, 36 insertions(+), 3 deletions(-)

Index: linux-2.6/include/linux/suspend.h
===================================================================
--- linux-2.6.orig/include/linux/suspend.h
+++ linux-2.6/include/linux/suspend.h
@@ -282,6 +282,8 @@ extern int unregister_pm_notifier(struct
{ .notifier_call = fn, .priority = pri }; \
register_pm_notifier(&fn##_nb); \
}
+
+extern bool pm_transition_in_progress(void);
#else /* !CONFIG_PM_SLEEP */

static inline int register_pm_notifier(struct notifier_block *nb)
@@ -295,6 +297,8 @@ static inline int unregister_pm_notifier
}

#define pm_notifier(fn, pri) do { (void)(fn); } while (0)
+
+static inline bool pm_transition_in_progress(void) { return false; }
#endif /* !CONFIG_PM_SLEEP */

#ifndef CONFIG_HIBERNATION
Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c
+++ linux-2.6/mm/page_alloc.c
@@ -1619,8 +1619,12 @@ nofail_alloc:
goto got_pg;
}

- /* The OOM killer will not help higher order allocs so fail */
- if (order > PAGE_ALLOC_COSTLY_ORDER) {
+ /*
+ * The OOM killer will not help higher order allocs and it is
+ * not useful during system-wide power transitions, so fail.
+ */
+ if (order > PAGE_ALLOC_COSTLY_ORDER
+ || pm_transition_in_progress()) {
clear_zonelist_oom(zonelist, gfp_mask);
goto nopage;
}
Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -299,9 +299,11 @@ int hibernation_snapshot(int platform_mo
{
int error;

+ transition_in_progress = true;
+
error = platform_begin(platform_mode);
if (error)
- return error;
+ goto Out;

/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
@@ -325,6 +327,9 @@ int hibernation_snapshot(int platform_mo
resume_console();
Close:
platform_end(platform_mode);
+
+ Out:
+ transition_in_progress = false;
return error;

Recover_platform:
@@ -607,6 +612,7 @@ int hibernate(void)
pr_debug("PM: Image restored successfully.\n");
swsusp_free();
}
+
Thaw:
thaw_processes();
Finish:
@@ -724,6 +730,8 @@ static int software_resume(void)
goto Done;
}

+ transition_in_progress = true;
+
pr_debug("PM: Reading hibernation image.\n");

error = swsusp_read(&flags);
@@ -732,6 +740,9 @@ static int software_resume(void)

printk(KERN_ERR "PM: Restore failed, recovering.\n");
swsusp_free();
+
+ transition_in_progress = false;
+
thaw_processes();
Done:
free_basic_memory_bitmaps();
Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -32,6 +32,13 @@ EXPORT_SYMBOL(pm_flags);

#ifdef CONFIG_PM_SLEEP

+bool transition_in_progress;
+
+bool pm_transition_in_progress(void)
+{
+ return transition_in_progress;
+}
+
/* Routines for PM-transition notifications */

static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
@@ -246,6 +253,8 @@ static int suspend_prepare(void)
goto Thaw;
}

+ transition_in_progress = true;
+
free_pages = global_page_state(NR_FREE_PAGES);
if (free_pages < FREE_PAGE_NUMBER) {
pr_debug("PM: free some memory\n");
@@ -258,6 +267,8 @@ static int suspend_prepare(void)
if (!error)
return 0;

+ transition_in_progress = false;
+
Thaw:
suspend_thaw_processes();
usermodehelper_enable();
@@ -403,6 +414,8 @@ int suspend_devices_and_enter(suspend_st
*/
static void suspend_finish(void)
{
+ transition_in_progress = false;
+
suspend_thaw_processes();
usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
Index: linux-2.6/kernel/power/power.h
===================================================================
--- linux-2.6.orig/kernel/power/power.h
+++ linux-2.6/kernel/power/power.h
@@ -173,6 +173,7 @@ static inline int suspend_devices_and_en
#ifdef CONFIG_PM_SLEEP
/* kernel/power/main.c */
extern int pm_notifier_call_chain(unsigned long val);
+extern bool transition_in_progress;
#endif

#ifdef CONFIG_HIGHMEM