commit 42e99bd975fd ("zram: optimize memory operations with
clear_page()/copy_page()") optimize page copy/clean operations, but
then commit d72e9a7a93e4 ("zram: do not use copy_page with non-page
aligned address") removes the optimization because there's memory
corruption at that time, the reason was well explained. But after
commit 1f7319c74275 ("zram: partial IO refactoring"), partial IO uses
alloc_page() instead of kmalloc to allocate a page, so we can bring
back the optimization.
commit 80ba4caf8ba9 ("zram: use copy_page for full page copy") brings
back partial optimization, missed one point in zram_write_page().
optimize the full page copying in zram_write_page() with copy_page()
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 3acd7006ad2c..4b2b5098062f 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1478,11 +1478,13 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
src = zstrm->buffer;
- if (comp_len == PAGE_SIZE)
+ if (comp_len == PAGE_SIZE) {
src = kmap_local_page(page);
- memcpy(dst, src, comp_len);
- if (comp_len == PAGE_SIZE)
+ copy_page(dst, src);
kunmap_local(src);
+ } else {
+ memcpy(dst, src, comp_len);
+ }
zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
zs_unmap_object(zram->mem_pool, handle);
--
2.43.0
