mm/pm: force GFP_NOIO during suspend/hibernation and resume
There are quite a few GFP_KERNEL memory allocations made during
suspend/hibernation and resume that may cause the system to hang, because
the I/O operations they depend on cannot be completed due to the
underlying devices being suspended.
Avoid this problem by clearing the __GFP_IO and __GFP_FS bits in
gfp_allowed_mask before suspend/hibernation and restoring the original
values of these bits in gfp_allowed_mask durig the subsequent resume.
[akpm@linux-foundation.org: fix CONFIG_PM=n linkage]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index e5567e6..2e1b32c 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -83,6 +83,7 @@
#define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
__GFP_HARDWALL | __GFP_HIGHMEM | \
__GFP_MOVABLE)
+#define GFP_IOFS (__GFP_IO | __GFP_FS)
#ifdef CONFIG_NUMA
#define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
@@ -337,9 +338,7 @@
extern gfp_t gfp_allowed_mask;
-static inline void set_gfp_allowed_mask(gfp_t mask)
-{
- gfp_allowed_mask = mask;
-}
+extern void set_gfp_allowed_mask(gfp_t mask);
+extern gfp_t clear_gfp_allowed_mask(gfp_t mask);
#endif /* __LINUX_GFP_H */
diff --git a/init/main.c b/init/main.c
index 40aaa02..41d0f10 100644
--- a/init/main.c
+++ b/init/main.c
@@ -618,7 +618,7 @@
local_irq_enable();
/* Interrupts are enabled now so all GFP allocations are safe. */
- set_gfp_allowed_mask(__GFP_BITS_MASK);
+ gfp_allowed_mask = __GFP_BITS_MASK;
kmem_cache_init_late();
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index bbfe472..da5288e 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -323,6 +323,7 @@
int hibernation_snapshot(int platform_mode)
{
int error;
+ gfp_t saved_mask;
error = platform_begin(platform_mode);
if (error)
@@ -334,6 +335,7 @@
goto Close;
suspend_console();
+ saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
error = dpm_suspend_start(PMSG_FREEZE);
if (error)
goto Recover_platform;
@@ -351,6 +353,7 @@
dpm_resume_end(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
+ set_gfp_allowed_mask(saved_mask);
resume_console();
Close:
platform_end(platform_mode);
@@ -445,14 +448,17 @@
int hibernation_restore(int platform_mode)
{
int error;
+ gfp_t saved_mask;
pm_prepare_console();
suspend_console();
+ saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
error = resume_target_kernel(platform_mode);
dpm_resume_end(PMSG_RECOVER);
}
+ set_gfp_allowed_mask(saved_mask);
resume_console();
pm_restore_console();
return error;
@@ -466,6 +472,7 @@
int hibernation_platform_enter(void)
{
int error;
+ gfp_t saved_mask;
if (!hibernation_ops)
return -ENOSYS;
@@ -481,6 +488,7 @@
entering_platform_hibernation = true;
suspend_console();
+ saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
error = dpm_suspend_start(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -518,6 +526,7 @@
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
+ set_gfp_allowed_mask(saved_mask);
resume_console();
Close:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 6f10dfc..44cce10 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -189,6 +189,7 @@
int suspend_devices_and_enter(suspend_state_t state)
{
int error;
+ gfp_t saved_mask;
if (!suspend_ops)
return -ENOSYS;
@@ -199,6 +200,7 @@
goto Close;
}
suspend_console();
+ saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
@@ -215,6 +217,7 @@
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
+ set_gfp_allowed_mask(saved_mask);
resume_console();
Close:
if (suspend_ops->end)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0734bed..298f307 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -76,6 +76,31 @@
int percpu_pagelist_fraction;
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
+#ifdef CONFIG_PM_SLEEP
+/*
+ * The following functions are used by the suspend/hibernate code to temporarily
+ * change gfp_allowed_mask in order to avoid using I/O during memory allocations
+ * while devices are suspended. To avoid races with the suspend/hibernate code,
+ * they should always be called with pm_mutex held (gfp_allowed_mask also should
+ * only be modified with pm_mutex held, unless the suspend/hibernate code is
+ * guaranteed not to run in parallel with that modification).
+ */
+void set_gfp_allowed_mask(gfp_t mask)
+{
+ WARN_ON(!mutex_is_locked(&pm_mutex));
+ gfp_allowed_mask = mask;
+}
+
+gfp_t clear_gfp_allowed_mask(gfp_t mask)
+{
+ gfp_t ret = gfp_allowed_mask;
+
+ WARN_ON(!mutex_is_locked(&pm_mutex));
+ gfp_allowed_mask &= ~mask;
+ return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif