path: root/mm/page_alloc.c
diff options
authorRafael J. Wysocki <>2010-03-05 13:42:13 -0800
committerLinus Torvalds <>2010-03-06 11:26:26 -0800
commit452aa6999e6703ffbddd7f6ea124d3968915f3e3 (patch)
tree48e375fdb60920675f68b444b462903ad8bb6940 /mm/page_alloc.c
parentad2bd7e0e9647cd48593a6b3a2be07dc2c2d28ed (diff)
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. [ fix CONFIG_PM=n linkage] Signed-off-by: Rafael J. Wysocki <> Reported-by: Maxim Levitsky <> Cc: Sebastian Ott <> Cc: Benjamin Herrenschmidt <> Cc: KOSAKI Motohiro <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm/page_alloc.c')
1 files changed, 25 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0734bedabd9..298f307c63a 100644
--- 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;
+ * 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 */
int pageblock_order __read_mostly;