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>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 6f10dfc2d3e9..44cce10b582d 100644
--- 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)