linux-kernel - [RFC PATCH 4/8] zram: handle ZRAM

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Message-ID: <20241118103054.3191944-5-senozhatsky@chromium.org>
Date: Mon, 18 Nov 2024 19:30:35 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Minchan Kim <minchan@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [RFC PATCH 4/8] zram: handle ZRAM_SAME immediately

Handling of ZRAM_SAME now uses a goto to the final stages of
zram_write_page() plus it introduces a branch and flags variable,
which is not making the code any simpler.  In reality, we can
handle ZRAM_SAME immediately when we detect such pages and
remove a goto and a branch.

Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 drivers/block/zram/zram_drv.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index e80b4d15b74b..76ff74a75125 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1625,7 +1625,6 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 	void *src, *dst, *mem;
 	struct zcomp_strm *zstrm;
 	unsigned long element = 0;
-	enum zram_pageflags flags = 0;
 
 	/* First, free memory allocated to this slot (if any) */
 	zram_slot_lock(zram, index);
@@ -1635,10 +1634,10 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 	mem = kmap_local_page(page);
 	if (page_same_filled(mem, &element)) {
 		kunmap_local(mem);
-		/* Free memory associated with this sector now. */
-		flags = ZRAM_SAME;
 		atomic64_inc(&zram->stats.same_pages);
-		goto out;
+		zram_set_flag(zram, index, ZRAM_SAME);
+		zram_set_handle(zram, index, element);
+		return 0;
 	}
 	kunmap_local(mem);
 
@@ -1719,7 +1718,7 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 	zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
 	zs_unmap_object(zram->mem_pool, handle);
 	atomic64_add(comp_len, &zram->stats.compr_data_size);
-out:
+
 	zram_slot_lock(zram, index);
 	if (comp_len == PAGE_SIZE) {
 		zram_set_flag(zram, index, ZRAM_HUGE);
@@ -1727,13 +1726,8 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 		atomic64_inc(&zram->stats.huge_pages_since);
 	}
 
-	if (flags) {
-		zram_set_flag(zram, index, flags);
-		zram_set_handle(zram, index, element);
-	}  else {
-		zram_set_handle(zram, index, handle);
-		zram_set_obj_size(zram, index, comp_len);
-	}
+	zram_set_handle(zram, index, handle);
+	zram_set_obj_size(zram, index, comp_len);
 	zram_slot_unlock(zram, index);
 
 	/* Update stats */
-- 
2.47.0.338.g60cca15819-goog