Merge branch 'akpm' (patchbomb from Andrew Morton)

Merge incoming from Andrew Morton:
 - Various misc things.
 - arch/sh updates.
 - Part of ocfs2.  Review is slow.
 - Slab updates.
 - Most of -mm.
 - printk updates.
 - lib/ updates.
 - checkpatch updates.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (226 commits)
  checkpatch: update $declaration_macros, add uninitialized_var
  checkpatch: warn on missing spaces in broken up quoted
  checkpatch: fix false positives for --strict "space after cast" test
  checkpatch: fix false positive MISSING_BREAK warnings with --file
  checkpatch: add test for native c90 types in unusual order
  checkpatch: add signed generic types
  checkpatch: add short int to c variable types
  checkpatch: add for_each tests to indentation and brace tests
  checkpatch: fix brace style misuses of else and while
  checkpatch: add --fix option for a couple OPEN_BRACE misuses
  checkpatch: use the correct indentation for which()
  checkpatch: add fix_insert_line and fix_delete_line helpers
  checkpatch: add ability to insert and delete lines to patch/file
  checkpatch: add an index variable for fixed lines
  checkpatch: warn on break after goto or return with same tab indentation
  checkpatch: emit a warning on file add/move/delete
  checkpatch: add test for commit id formatting style in commit log
  checkpatch: emit fewer kmalloc_array/kcalloc conversion warnings
  checkpatch: improve "no space after cast" test
  checkpatch: allow multiple const * types
  ...

1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 7f21c145e317..5b0afde729cd 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -43,7 +43,6 @@ static const size_t max_zpage_size = PAGE_SIZE / 4 * 3;
 /*-- End of configurable params */
 
 #define SECTOR_SHIFT		9
-#define SECTOR_SIZE		(1 << SECTOR_SHIFT)
 #define SECTORS_PER_PAGE_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define SECTORS_PER_PAGE	(1 << SECTORS_PER_PAGE_SHIFT)
 #define ZRAM_LOGICAL_BLOCK_SHIFT 12
@@ -51,10 +50,24 @@ static const size_t max_zpage_size = PAGE_SIZE / 4 * 3;
 #define ZRAM_SECTOR_PER_LOGICAL_BLOCK	\
 	(1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT))
 
-/* Flags for zram pages (table[page_no].flags) */
+
+/*
+ * The lower ZRAM_FLAG_SHIFT bits of table.value is for
+ * object size (excluding header), the higher bits is for
+ * zram_pageflags.
+ *
+ * zram is mainly used for memory efficiency so we want to keep memory
+ * footprint small so we can squeeze size and flags into a field.
+ * The lower ZRAM_FLAG_SHIFT bits is for object size (excluding header),
+ * the higher bits is for zram_pageflags.
+ */
+#define ZRAM_FLAG_SHIFT 24
+
+/* Flags for zram pages (table[page_no].value) */
 enum zram_pageflags {
 	/* Page consists entirely of zeros */
-	ZRAM_ZERO,
+	ZRAM_ZERO = ZRAM_FLAG_SHIFT + 1,
+	ZRAM_ACCESS,	/* page in now accessed */
 
 	__NR_ZRAM_PAGEFLAGS,
 };
@@ -62,11 +75,10 @@ enum zram_pageflags {
 /*-- Data structures */
 
 /* Allocated for each disk page */
-struct table {
+struct zram_table_entry {
 	unsigned long handle;
-	u16 size;	/* object size (excluding header) */
-	u8 flags;
-} __aligned(4);
+	unsigned long value;
+};
 
 struct zram_stats {
 	atomic64_t compr_data_size;	/* compressed size of pages stored */
@@ -81,8 +93,7 @@ struct zram_stats {
 };
 
 struct zram_meta {
-	rwlock_t tb_lock;	/* protect table */
-	struct table *table;
+	struct zram_table_entry *table;
 	struct zs_pool *mem_pool;
 };