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 (file)
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -83,6 +83,7 @@ struct vm_area_struct;
 #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 @@ void drain_local_pages(void *dummy);
 
 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 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -618,7 +618,7 @@ asmlinkage void __init start_kernel(void)
        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 (file)
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -323,6 +323,7 @@ static int create_image(int platform_mode)
 int hibernation_snapshot(int platform_mode)
 {
        int error;
+       gfp_t saved_mask;
 
        error = platform_begin(platform_mode);
        if (error)
@@ -334,6 +335,7 @@ int hibernation_snapshot(int platform_mode)
                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 @@ int hibernation_snapshot(int platform_mode)
 
        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 @@ static int resume_target_kernel(bool platform_mode)
 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_restore(int platform_mode)
 int hibernation_platform_enter(void)
 {
        int error;
+       gfp_t saved_mask;
 
        if (!hibernation_ops)
                return -ENOSYS;
@@ -481,6 +488,7 @@ int hibernation_platform_enter(void)
 
        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 @@ int hibernation_platform_enter(void)
  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 (file)
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -189,6 +189,7 @@ static int suspend_enter(suspend_state_t state)
 int suspend_devices_and_enter(suspend_state_t state)
 {
        int error;
+       gfp_t saved_mask;
 
        if (!suspend_ops)
                return -ENOSYS;
@@ -199,6 +200,7 @@ int suspend_devices_and_enter(suspend_state_t state)
                        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 @@ int suspend_devices_and_enter(suspend_state_t state)
        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 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -76,6 +76,31 @@ unsigned long totalreserve_pages __read_mostly;
 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