Merge tag 'drm-intel-fixes-2013-06-04' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes

Daniel writes:

Three regression fixes and one no-lvds quirk update. The regression Egbert
Eich tracked down goes back to 2.6.37 ... ugh. The other two are pretty
minor: One bogus modeset state checker WARN and a patch to prevent X
dying in a SIGBUS after a gpu hang with failed (or not implement as on
gen2/3) gpu reset.

* tag 'drm-intel-fixes-2013-06-04' of git://people.freedesktop.org/~danvet/drm-intel: (368 commits)
  drm/i915/sdvo: Use &intel_sdvo->ddc instead of intel_sdvo->i2c for DDC.
  drm/i915: no lvds quirk for hp t5740
  drm/i915: Quirk the pipe A quirk in the modeset state checker
  drm/i915: Fix spurious -EIO/SIGBUS on wedged gpus
  Linux 3.10-rc4
  parisc: parport0: fix this legacy no-device port driver!
  parport_pc: disable PARPORT_PC_SUPERIO on parisc architecture
  parisc/PCI: lba: fix: convert to pci_create_root_bus() for correct root bus resources (v2)
  parisc/PCI: Set type for LBA bus_num resource
  MAINTAINERS: update parisc architecture file list
  parisc: kernel: using strlcpy() instead of strcpy()
  parisc: rename "CONFIG_PA7100" to "CONFIG_PA7000"
  parisc: fix kernel BUG at arch/parisc/include/asm/mmzone.h:50
  parisc: memory overflow, 'name' length is too short for using
  powerpc/cputable: Fix typo on P7+ cputable entry
  powerpc/perf: Add missing SIER support
  powerpc/perf: Revert to original NO_SIPR logic
  powerpc/pci: Remove the unused variables in pci_process_bridge_OF_ranges
  powerpc/pci: Remove the stale comments of pci_process_bridge_OF_ranges
  powerpc/pseries: Always enable CONFIG_HOTPLUG_CPU on PSERIES SMP
  ...

1 files changed, 12 insertions, 2 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cb1c9dedf9b6..010d6c14129a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4108,8 +4108,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
         if (mem_cgroup_disabled())
                 return NULL;
 
-        VM_BUG_ON(PageSwapCache(page));
-
         if (PageTransHuge(page)) {
                 nr_pages <<= compound_order(page);
                 VM_BUG_ON(!PageTransHuge(page));
@@ -4205,6 +4203,18 @@ void mem_cgroup_uncharge_page(struct page *page)
         if (page_mapped(page))
                 return;
         VM_BUG_ON(page->mapping && !PageAnon(page));
+        /*
+         * If the page is in swap cache, uncharge should be deferred
+         * to the swap path, which also properly accounts swap usage
+         * and handles memcg lifetime.
+         *
+         * Note that this check is not stable and reclaim may add the
+         * page to swap cache at any time after this.  However, if the
+         * page is not in swap cache by the time page->mapcount hits
+         * 0, there won't be any page table references to the swap
+         * slot, and reclaim will free it and not actually write the
+         * page to disk.
+         */
         if (PageSwapCache(page))
                 return;
         __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);