The patch titled mm, PM/Freezer: Disable OOM killer when tasks are frozen has been added to the -mm tree. Its filename is mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm, PM/Freezer: Disable OOM killer when tasks are frozen From: Rafael J. Wysocki <rjw@xxxxxxx> Currently, the following scenario appears to be possible in theory: * Tasks are frozen for hibernation or suspend. * Free pages are almost exhausted. * Certain piece of code in the suspend code path attempts to allocate some memory using GFP_KERNEL and allocation order less than or equal to PAGE_ALLOC_COSTLY_ORDER. * __alloc_pages_internal() cannot find a free page so it invokes the OOM killer. * The OOM killer attempts to kill a task, but the task is frozen, so it doesn't die immediately. * __alloc_pages_internal() jumps to 'restart', unsuccessfully tries to find a free page and invokes the OOM killer. * No progress can be made. Although it is now hard to trigger during hibernation due to the memory shrinking carried out by the hibernation code, it is theoretically possible to trigger during suspend after the memory shrinking has been removed from that code path. Moreover, since memory allocations are going to be used for the hibernation memory shrinking, it will be even more likely to happen during hibernation. To prevent it from happening, introduce the oom_killer_disabled switch that will cause __alloc_pages_internal() to fail in the situations in which the OOM killer would have been called and make the freezer set this switch after tasks have been successfully frozen. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Mel Gorman <mel@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/gfp.h | 12 ++++++++++++ kernel/power/process.c | 5 +++++ mm/page_alloc.c | 4 ++++ 3 files changed, 21 insertions(+) diff -puN include/linux/gfp.h~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen include/linux/gfp.h --- a/include/linux/gfp.h~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen +++ a/include/linux/gfp.h @@ -240,4 +240,16 @@ void drain_zone_pages(struct zone *zone, void drain_all_pages(void); void drain_local_pages(void *dummy); +extern bool oom_killer_disabled; + +static inline void disable_oom_killer(void) +{ + oom_killer_disabled = true; +} + +static inline void enable_oom_killer(void) +{ + oom_killer_disabled = false; +} + #endif /* __LINUX_GFP_H */ diff -puN kernel/power/process.c~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen kernel/power/process.c --- a/kernel/power/process.c~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen +++ a/kernel/power/process.c @@ -117,9 +117,12 @@ int freeze_processes(void) if (error) goto Exit; printk("done."); + + disable_oom_killer(); Exit: BUG_ON(in_atomic()); printk("\n"); + return error; } @@ -145,6 +148,8 @@ static void thaw_tasks(bool nosig_only) void thaw_processes(void) { + enable_oom_killer(); + printk("Restarting tasks ... "); thaw_tasks(true); thaw_tasks(false); diff -puN mm/page_alloc.c~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen mm/page_alloc.c --- a/mm/page_alloc.c~mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen +++ a/mm/page_alloc.c @@ -180,6 +180,8 @@ static void set_pageblock_migratetype(st PB_migrate, PB_migrate_end); } +bool oom_killer_disabled __read_mostly; + #ifdef CONFIG_DEBUG_VM static int page_outside_zone_boundaries(struct zone *zone, struct page *page) { @@ -1770,6 +1772,8 @@ rebalance: */ if (!did_some_progress) { if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { + if (oom_killer_disabled) + goto nopage; page = __alloc_pages_may_oom(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, _ Patches currently in -mm which might be from rjw@xxxxxxx are linux-next.patch devpts-correctly-set-default-options.patch mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen.patch mm-pm-freezer-disable-oom-killer-when-tasks-are-frozen-fix.patch shrink_slab-handle-bad-shrinkers.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html