Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 27 insertions, 35 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 6fe7d15bd1f7..11ff8f758631 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1169,6 +1169,7 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,
 	unsigned long balanced_dirty_ratelimit;
 	unsigned long step;
 	unsigned long x;
+	unsigned long shift;
 
 	/*
 	 * The dirty rate will match the writeout rate in long term, except
@@ -1293,11 +1294,11 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,
 	 * rate itself is constantly fluctuating. So decrease the track speed
 	 * when it gets close to the target. Helps eliminate pointless tremors.
 	 */
-	step >>= dirty_ratelimit / (2 * step + 1);
-	/*
-	 * Limit the tracking speed to avoid overshooting.
-	 */
-	step = (step + 7) / 8;
+	shift = dirty_ratelimit / (2 * step + 1);
+	if (shift < BITS_PER_LONG)
+		step = DIV_ROUND_UP(step >> shift, 8);
+	else
+		step = 0;
 
 	if (dirty_ratelimit < balanced_dirty_ratelimit)
 		dirty_ratelimit += step;
@@ -2409,12 +2410,11 @@ int __set_page_dirty_no_writeback(struct page *page)
 /*
  * Helper function for set_page_dirty family.
  *
- * Caller must hold mem_cgroup_begin_page_stat().
+ * Caller must hold lock_page_memcg().
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-void account_page_dirtied(struct page *page, struct address_space *mapping,
-			  struct mem_cgroup *memcg)
+void account_page_dirtied(struct page *page, struct address_space *mapping)
 {
 	struct inode *inode = mapping->host;
 
@@ -2426,7 +2426,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping,
 		inode_attach_wb(inode, page);
 		wb = inode_to_wb(inode);
 
-		mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_DIRTY);
 		__inc_zone_page_state(page, NR_FILE_DIRTY);
 		__inc_zone_page_state(page, NR_DIRTIED);
 		__inc_wb_stat(wb, WB_RECLAIMABLE);
@@ -2441,13 +2441,13 @@ EXPORT_SYMBOL(account_page_dirtied);
 /*
  * Helper function for deaccounting dirty page without writeback.
  *
- * Caller must hold mem_cgroup_begin_page_stat().
+ * Caller must hold lock_page_memcg().
  */
 void account_page_cleaned(struct page *page, struct address_space *mapping,
-			  struct mem_cgroup *memcg, struct bdi_writeback *wb)
+			  struct bdi_writeback *wb)
 {
 	if (mapping_cap_account_dirty(mapping)) {
-		mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
 		dec_zone_page_state(page, NR_FILE_DIRTY);
 		dec_wb_stat(wb, WB_RECLAIMABLE);
 		task_io_account_cancelled_write(PAGE_CACHE_SIZE);
@@ -2468,26 +2468,24 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
  */
 int __set_page_dirty_nobuffers(struct page *page)
 {
-	struct mem_cgroup *memcg;
-
-	memcg = mem_cgroup_begin_page_stat(page);
+	lock_page_memcg(page);
 	if (!TestSetPageDirty(page)) {
 		struct address_space *mapping = page_mapping(page);
 		unsigned long flags;
 
 		if (!mapping) {
-			mem_cgroup_end_page_stat(memcg);
+			unlock_page_memcg(page);
 			return 1;
 		}
 
 		spin_lock_irqsave(&mapping->tree_lock, flags);
 		BUG_ON(page_mapping(page) != mapping);
 		WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
-		account_page_dirtied(page, mapping, memcg);
+		account_page_dirtied(page, mapping);
 		radix_tree_tag_set(&mapping->page_tree, page_index(page),
 				   PAGECACHE_TAG_DIRTY);
 		spin_unlock_irqrestore(&mapping->tree_lock, flags);
-		mem_cgroup_end_page_stat(memcg);
+		unlock_page_memcg(page);
 
 		if (mapping->host) {
 			/* !PageAnon && !swapper_space */
@@ -2495,7 +2493,7 @@ int __set_page_dirty_nobuffers(struct page *page)
 		}
 		return 1;
 	}
-	mem_cgroup_end_page_stat(memcg);
+	unlock_page_memcg(page);
 	return 0;
 }
 EXPORT_SYMBOL(__set_page_dirty_nobuffers);
@@ -2625,17 +2623,16 @@ void cancel_dirty_page(struct page *page)
 	if (mapping_cap_account_dirty(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
-		struct mem_cgroup *memcg;
 		bool locked;
 
-		memcg = mem_cgroup_begin_page_stat(page);
+		lock_page_memcg(page);
 		wb = unlocked_inode_to_wb_begin(inode, &locked);
 
 		if (TestClearPageDirty(page))
-			account_page_cleaned(page, mapping, memcg, wb);
+			account_page_cleaned(page, mapping, wb);
 
 		unlocked_inode_to_wb_end(inode, locked);
-		mem_cgroup_end_page_stat(memcg);
+		unlock_page_memcg(page);
 	} else {
 		ClearPageDirty(page);
 	}
@@ -2666,7 +2663,6 @@ int clear_page_dirty_for_io(struct page *page)
 	if (mapping && mapping_cap_account_dirty(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
-		struct mem_cgroup *memcg;
 		bool locked;
 
 		/*
@@ -2704,16 +2700,14 @@ int clear_page_dirty_for_io(struct page *page)
 		 * always locked coming in here, so we get the desired
 		 * exclusion.
 		 */
-		memcg = mem_cgroup_begin_page_stat(page);
 		wb = unlocked_inode_to_wb_begin(inode, &locked);
 		if (TestClearPageDirty(page)) {
-			mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+			mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
 			dec_zone_page_state(page, NR_FILE_DIRTY);
 			dec_wb_stat(wb, WB_RECLAIMABLE);
 			ret = 1;
 		}
 		unlocked_inode_to_wb_end(inode, locked);
-		mem_cgroup_end_page_stat(memcg);
 		return ret;
 	}
 	return TestClearPageDirty(page);
@@ -2723,10 +2717,9 @@ EXPORT_SYMBOL(clear_page_dirty_for_io);
 int test_clear_page_writeback(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
-	struct mem_cgroup *memcg;
 	int ret;
 
-	memcg = mem_cgroup_begin_page_stat(page);
+	lock_page_memcg(page);
 	if (mapping) {
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
@@ -2750,21 +2743,20 @@ int test_clear_page_writeback(struct page *page)
 		ret = TestClearPageWriteback(page);
 	}
 	if (ret) {
-		mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
 		dec_zone_page_state(page, NR_WRITEBACK);
 		inc_zone_page_state(page, NR_WRITTEN);
 	}
-	mem_cgroup_end_page_stat(memcg);
+	unlock_page_memcg(page);
 	return ret;
 }
 
 int __test_set_page_writeback(struct page *page, bool keep_write)
 {
 	struct address_space *mapping = page_mapping(page);
-	struct mem_cgroup *memcg;
 	int ret;
 
-	memcg = mem_cgroup_begin_page_stat(page);
+	lock_page_memcg(page);
 	if (mapping) {
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
@@ -2792,10 +2784,10 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
 		ret = TestSetPageWriteback(page);
 	}
 	if (!ret) {
-		mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
 		inc_zone_page_state(page, NR_WRITEBACK);
 	}
-	mem_cgroup_end_page_stat(memcg);
+	unlock_page_memcg(page);
 	return ret;
 
 }