Merge branch 'akpm' (Andrew's patch-bomb)

Merge patches through Andrew Morton:
 "180 patches - err 181 - listed below:

   - most of MM.  I held back the (large) "memcg: add hugetlb extension"
     series because a bunfight has recently broken out.

   - leds.  After this, Bryan Wu will be handling drivers/leds/

   - backlight

   - lib/

   - rtc"

* emailed from Andrew Morton <akpm@linux-foundation.org>: (181 patches)
  drivers/rtc/rtc-s3c.c: fix compiler warning
  drivers/rtc/rtc-tegra.c: clean up probe/remove routines
  drivers/rtc/rtc-pl031.c: remove RTC timer interrupt handling
  drivers/rtc/rtc-lpc32xx.c: add device tree support
  drivers/rtc/rtc-m41t93.c: don't let get_time() reset M41T93_FLAG_OF
  rtc: ds1307: add trickle charger support
  rtc: ds1307: remove superfluous initialization
  rtc: rename CONFIG_RTC_MXC to CONFIG_RTC_DRV_MXC
  drivers/rtc/Kconfig: place RTC_DRV_IMXDI and RTC_MXC under "on-CPU RTC drivers"
  drivers/rtc/rtc-pcf8563.c: add RTC_VL_READ/RTC_VL_CLR ioctl feature
  rtc: add ioctl to get/clear battery low voltage status
  drivers/rtc/rtc-ep93xx.c: convert to use module_platform_driver()
  rtc/spear: add Device Tree probing capability
  lib/vsprintf.c: "%#o",0 becomes '0' instead of '00'
  radix-tree: fix preload vector size
  spinlock_debug: print kallsyms name for lock
  vsprintf: fix %ps on non symbols when using kallsyms
  lib/bitmap.c: fix documentation for scnprintf() functions
  lib/string_helpers.c: make arrays static
  lib/test-kstrtox.c: mark const init data with __initconst instead of __initdata
  ...

1 files changed, 16 insertions, 4 deletions

diff --git a/mm/memory.c b/mm/memory.c
index e40f6759ba9..1b7dc662bf9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2908,7 +2908,6 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	delayacct_set_flag(DELAYACCT_PF_SWAPIN);
 	page = lookup_swap_cache(entry);
 	if (!page) {
-		grab_swap_token(mm); /* Contend for token _before_ read-in */
 		page = swapin_readahead(entry,
 					GFP_HIGHUSER_MOVABLE, vma, address);
 		if (!page) {
@@ -2938,6 +2937,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	}
 
 	locked = lock_page_or_retry(page, mm, flags);
+
 	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 	if (!locked) {
 		ret |= VM_FAULT_RETRY;
@@ -3486,6 +3486,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		return hugetlb_fault(mm, vma, address, flags);
 
+retry:
 	pgd = pgd_offset(mm, address);
 	pud = pud_alloc(mm, pgd, address);
 	if (!pud)
@@ -3499,13 +3500,24 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 							  pmd, flags);
 	} else {
 		pmd_t orig_pmd = *pmd;
+		int ret;
+
 		barrier();
 		if (pmd_trans_huge(orig_pmd)) {
 			if (flags & FAULT_FLAG_WRITE &&
 			    !pmd_write(orig_pmd) &&
-			    !pmd_trans_splitting(orig_pmd))
-				return do_huge_pmd_wp_page(mm, vma, address,
-							   pmd, orig_pmd);
+			    !pmd_trans_splitting(orig_pmd)) {
+				ret = do_huge_pmd_wp_page(mm, vma, address, pmd,
+							  orig_pmd);
+				/*
+				 * If COW results in an oom, the huge pmd will
+				 * have been split, so retry the fault on the
+				 * pte for a smaller charge.
+				 */
+				if (unlikely(ret & VM_FAULT_OOM))
+					goto retry;
+				return ret;
+			}
 			return 0;
 		}
 	}