[PATCHv4 1/6] zram: introduce ZRAM_PP_SLOT flag

[Sergey Senozhatsky]

This flag indicates that the slot was selected as a
candidate slot for post-processing (pp) and was assigned
to a pp bucket.  It does not necessarily mean that the
slot is currently under post-processing, but may mean
so.  The slot can loose its PP_SLOT flag, while still
being in the pp-bucket, if it's accessed or slot_free-ed.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
 drivers/block/zram/zram_drv.c | 2 ++
 drivers/block/zram/zram_drv.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index ee2a279c5f25..d170bf6cdcd8 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -178,6 +178,7 @@ static inline u32 zram_get_priority(struct zram *zram, u32 index)
 static void zram_accessed(struct zram *zram, u32 index)
 {
 	zram_clear_flag(zram, index, ZRAM_IDLE);
+	zram_clear_flag(zram, index, ZRAM_PP_SLOT);
 #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
 	zram->table[index].ac_time = ktime_get_boottime();
 #endif
@@ -1354,6 +1355,7 @@ static void zram_free_page(struct zram *zram, size_t index)
 		zram_clear_flag(zram, index, ZRAM_INCOMPRESSIBLE);
 
 	zram_set_priority(zram, index, 0);
+	zram_clear_flag(zram, index, ZRAM_PP_SLOT);
 
 	if (zram_test_flag(zram, index, ZRAM_WB)) {
 		zram_clear_flag(zram, index, ZRAM_WB);
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index cfc8c059db63..914cb6629969 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -48,6 +48,7 @@ enum zram_pageflags {
 	ZRAM_SAME = ZRAM_FLAG_SHIFT,	/* Page consists the same element */
 	ZRAM_WB,	/* page is stored on backing_device */
 	ZRAM_UNDER_WB,	/* page is under writeback */
+	ZRAM_PP_SLOT,	/* Selected for post-processing */
 	ZRAM_HUGE,	/* Incompressible page */
 	ZRAM_IDLE,	/* not accessed page since last idle marking */
 	ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */
-- 
2.46.0.598.g6f2099f65c-goog