[PATCH v4 6/8] zram: Convert to using memset_l

From: Matthew Wilcox
Date: Thu Jul 20 2017 - 14:47:14 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

zram was the motivation for creating memset_l(). Minchan Kim sees a 7%
performance improvement on x86 with 100MB of non-zero deduplicatable
data:

perf stat -r 10 dd if=/dev/zram0 of=/dev/null

vanilla: 0.232050465 seconds time elapsed ( +- 0.51% )
memset_l: 0.217219387 seconds time elapsed ( +- 0.07% )

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Tested-by: Minchan Kim <minchan@xxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 856d5dc02451..2df50d82dc29 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -175,20 +175,11 @@ static inline void update_used_max(struct zram *zram,
} while (old_max != cur_max);
}

-static inline void zram_fill_page(char *ptr, unsigned long len,
+static inline void zram_fill_page(void *ptr, unsigned long len,
unsigned long value)
{
- int i;
- unsigned long *page = (unsigned long *)ptr;
-
WARN_ON_ONCE(!IS_ALIGNED(len, sizeof(unsigned long)));
-
- if (likely(value == 0)) {
- memset(ptr, 0, len);
- } else {
- for (i = 0; i < len / sizeof(*page); i++)
- page[i] = value;
- }
+ memset_l(ptr, value, len / sizeof(unsigned long));
}

static bool page_same_filled(void *ptr, unsigned long *element)
--
2.13.2