Merge tag 'v3.8-rc3' into v4l_for_linus

Linux 3.8-rc3

* tag 'v3.8-rc3': (11110 commits)
  Linux 3.8-rc3
  mm: reinstante dropped pmd_trans_splitting() check
  cred: Remove tgcred pointer from struct cred
  drm/ttm: fix fence locking in ttm_buffer_object_transfer
  ARM: clps711x: Fix bad merge of clockevents setup
  ARM: highbank: save and restore L2 cache and GIC on suspend
  ARM: highbank: add a power request clear
  ARM: highbank: fix secondary boot and hotplug
  ARM: highbank: fix typos with hignbank in power request functions
  ARM: dts: fix highbank cpu mpidr values
  ARM: dts: add device_type prop to cpu nodes on Calxeda platforms
  drm/prime: drop reference on imported dma-buf come from gem
  xen/netfront: improve truesize tracking
  ARM: mx5: Fix MX53 flexcan2 clock
  ARM: OMAP2+: am33xx-hwmod: Fix wrongly terminated am33xx_usbss_mpu_irqs array
  sctp: fix Kconfig bug in default cookie hmac selection
  EDAC: Cleanup device deregistering path
  EDAC: Fix EDAC Kconfig menu
  EDAC: Fix kernel panic on module unloading
  ALSA: hda - add mute LED for HP Pavilion 17 (Realtek codec)
  ...

1 files changed, 25 insertions, 11 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 830893b2b3c..0713bfbf095 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -201,6 +201,18 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
 		     zone_reclaimable_pages(z) - z->dirty_balance_reserve;
 	}
 	/*
+	 * Unreclaimable memory (kernel memory or anonymous memory
+	 * without swap) can bring down the dirtyable pages below
+	 * the zone's dirty balance reserve and the above calculation
+	 * will underflow.  However we still want to add in nodes
+	 * which are below threshold (negative values) to get a more
+	 * accurate calculation but make sure that the total never
+	 * underflows.
+	 */
+	if ((long)x < 0)
+		x = 0;
+
+	/*
 	 * Make sure that the number of highmem pages is never larger
 	 * than the number of the total dirtyable memory. This can only
 	 * occur in very strange VM situations but we want to make sure
@@ -222,8 +234,8 @@ static unsigned long global_dirtyable_memory(void)
 {
 	unsigned long x;
 
-	x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages() -
-	    dirty_balance_reserve;
+	x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
+	x -= min(x, dirty_balance_reserve);
 
 	if (!vm_highmem_is_dirtyable)
 		x -= highmem_dirtyable_memory(x);
@@ -290,9 +302,12 @@ static unsigned long zone_dirtyable_memory(struct zone *zone)
 	 * highmem zone can hold its share of dirty pages, so we don't
 	 * care about vm_highmem_is_dirtyable here.
 	 */
-	return zone_page_state(zone, NR_FREE_PAGES) +
-	       zone_reclaimable_pages(zone) -
-	       zone->dirty_balance_reserve;
+	unsigned long nr_pages = zone_page_state(zone, NR_FREE_PAGES) +
+		zone_reclaimable_pages(zone);
+
+	/* don't allow this to underflow */
+	nr_pages -= min(nr_pages, zone->dirty_balance_reserve);
+	return nr_pages;
 }
 
 /**
@@ -1069,7 +1084,7 @@ static void bdi_update_bandwidth(struct backing_dev_info *bdi,
 }
 
 /*
- * After a task dirtied this many pages, balance_dirty_pages_ratelimited_nr()
+ * After a task dirtied this many pages, balance_dirty_pages_ratelimited()
  * will look to see if it needs to start dirty throttling.
  *
  * If dirty_poll_interval is too low, big NUMA machines will call the expensive
@@ -1436,9 +1451,8 @@ static DEFINE_PER_CPU(int, bdp_ratelimits);
 DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
 
 /**
- * balance_dirty_pages_ratelimited_nr - balance dirty memory state
+ * balance_dirty_pages_ratelimited - balance dirty memory state
  * @mapping: address_space which was dirtied
- * @nr_pages_dirtied: number of pages which the caller has just dirtied
  *
  * Processes which are dirtying memory should call in here once for each page
  * which was newly dirtied.  The function will periodically check the system's
@@ -1449,8 +1463,7 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
  * limit we decrease the ratelimiting by a lot, to prevent individual processes
  * from overshooting the limit by (ratelimit_pages) each.
  */
-void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
-					unsigned long nr_pages_dirtied)
+void balance_dirty_pages_ratelimited(struct address_space *mapping)
 {
 	struct backing_dev_info *bdi = mapping->backing_dev_info;
 	int ratelimit;
@@ -1484,6 +1497,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 	 */
 	p = &__get_cpu_var(dirty_throttle_leaks);
 	if (*p > 0 && current->nr_dirtied < ratelimit) {
+		unsigned long nr_pages_dirtied;
 		nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied);
 		*p -= nr_pages_dirtied;
 		current->nr_dirtied += nr_pages_dirtied;
@@ -1493,7 +1507,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 	if (unlikely(current->nr_dirtied >= ratelimit))
 		balance_dirty_pages(mapping, current->nr_dirtied);
 }
-EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
+EXPORT_SYMBOL(balance_dirty_pages_ratelimited);
 
 void throttle_vm_writeout(gfp_t gfp_mask)
 {