From 452aa6999e6703ffbddd7f6ea124d3968915f3e3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 5 Mar 2010 13:42:13 -0800 Subject: 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 Reported-by: Maxim Levitsky Cc: Sebastian Ott Cc: Benjamin Herrenschmidt Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'mm') 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; +#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 -- cgit v1.2.3