[PATCH] zram: Use kmap_local_page()

[PATCH] zram: Use kmap_local_page()

[Sergey Senozhatsky]

Use kmap_local_page() instead of kmap_atomic() which has been
deprecated.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/block/zram/zram_drv.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index f6b286e7f310..2b1d82473be8 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1321,9 +1321,9 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
 		void *mem;
 
 		value = handle ? zram_get_element(zram, index) : 0;
-		mem = kmap_atomic(page);
+		mem = kmap_local_page(page);
 		zram_fill_page(mem, PAGE_SIZE, value);
-		kunmap_atomic(mem);
+		kunmap_local(mem);
 		return 0;
 	}
 
@@ -1336,14 +1336,14 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
 
 	src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
 	if (size == PAGE_SIZE) {
-		dst = kmap_atomic(page);
+		dst = kmap_local_page(page);
 		memcpy(dst, src, PAGE_SIZE);
-		kunmap_atomic(dst);
+		kunmap_local(dst);
 		ret = 0;
 	} else {
-		dst = kmap_atomic(page);
+		dst = kmap_local_page(page);
 		ret = zcomp_decompress(zstrm, src, size, dst);
-		kunmap_atomic(dst);
+		kunmap_local(dst);
 		zcomp_stream_put(zram->comps[prio]);
 	}
 	zs_unmap_object(zram->mem_pool, handle);
@@ -1416,21 +1416,21 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 	unsigned long element = 0;
 	enum zram_pageflags flags = 0;
 
-	mem = kmap_atomic(page);
+	mem = kmap_local_page(page);
 	if (page_same_filled(mem, &element)) {
-		kunmap_atomic(mem);
+		kunmap_local(mem);
 		/* Free memory associated with this sector now. */
 		flags = ZRAM_SAME;
 		atomic64_inc(&zram->stats.same_pages);
 		goto out;
 	}
-	kunmap_atomic(mem);
+	kunmap_local(mem);
 
 compress_again:
 	zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]);
-	src = kmap_atomic(page);
+	src = kmap_local_page(page);
 	ret = zcomp_compress(zstrm, src, &comp_len);
-	kunmap_atomic(src);
+	kunmap_local(src);
 
 	if (unlikely(ret)) {
 		zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
@@ -1494,10 +1494,10 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 
 	src = zstrm->buffer;
 	if (comp_len == PAGE_SIZE)
-		src = kmap_atomic(page);
+		src = kmap_local_page(page);
 	memcpy(dst, src, comp_len);
 	if (comp_len == PAGE_SIZE)
-		kunmap_atomic(src);
+		kunmap_local(src);
 
 	zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
 	zs_unmap_object(zram->mem_pool, handle);
@@ -1614,9 +1614,9 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page,
 
 		num_recomps++;
 		zstrm = zcomp_stream_get(zram->comps[prio]);
-		src = kmap_atomic(page);
+		src = kmap_local_page(page);
 		ret = zcomp_compress(zstrm, src, &comp_len_new);
-		kunmap_atomic(src);
+		kunmap_local(src);
 
 		if (ret) {
 			zcomp_stream_put(zram->comps[prio]);
-- 
2.43.0.rc1.413.gea7ed67945-goog

Re: [PATCH] zram: Use kmap_local_page()

[Minchan Kim]

On Tue, Nov 28, 2023 at 05:22:07PM +0900, Sergey Senozhatsky wrote:
> Use kmap_local_page() instead of kmap_atomic() which has been
> deprecated.
> 
> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>

I didn't know that the kmap_atomic was deprecated.

Thanks.

Re: [PATCH] zram: Use kmap_local_page()

[Sergey Senozhatsky]

On (23/11/28 16:01), Minchan Kim wrote:
> On Tue, Nov 28, 2023 at 05:22:07PM +0900, Sergey Senozhatsky wrote:
> > Use kmap_local_page() instead of kmap_atomic() which has been
> > deprecated.
> > 
> > Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Acked-by: Minchan Kim <minchan@kernel.org>

Thanks.

> I didn't know that the kmap_atomic was deprecated.

Me neither, figured it out recently (via checkpatch warning).
https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/

We need to take a look at zsmalloc, the conversion can be a little more
difficult than zram's.