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From: Matthew Wilcox <willy@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-alpha@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, x86@kernel.org,
	linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org,
	sparclinux@vger.kernel.org, Minchan Kim <minchan@kernel.org>,
	Matthew Wilcox <mawilcox@microsoft.com>
Subject: [PATCH v3 5/7] zram: Convert to using memset_l
Date: Fri, 24 Mar 2017 09:13:16 -0700	[thread overview]
Message-ID: <20170324161318.18718-6-willy@infradead.org> (raw)
In-Reply-To: <20170324161318.18718-1-willy@infradead.org>

From: Matthew Wilcox <mawilcox@microsoft.com>

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@microsoft.com>
Tested-by: Minchan Kim <minchan@kernel.org>
---
 drivers/block/zram/zram_drv.c | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index e27d89a36c34..25dcad309695 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -157,20 +157,11 @@ 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)
@@ -193,7 +184,7 @@ static bool page_same_filled(void *ptr, unsigned long *element)
 static void handle_same_page(struct bio_vec *bvec, unsigned long element)
 {
 	struct page *page = bvec->bv_page;
-	void *user_mem;
+	char *user_mem;
 
 	user_mem = kmap_atomic(page);
 	zram_fill_page(user_mem + bvec->bv_offset, bvec->bv_len, element);
-- 
2.11.0

  parent reply	other threads:[~2017-03-24 16:16 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-24 16:13 [PATCH v3 0/7] Add memsetN functions Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 1/7] Add multibyte memset functions Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 2/7] ARM: Implement memset16, memset32 & memset64 Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 3/7] x86: " Matthew Wilcox
2017-03-26  7:44   ` kbuild test robot
2017-03-24 16:13 ` [PATCH v3 4/7] alpha: Add support for memset16 Matthew Wilcox
2017-03-26  7:28   ` kbuild test robot
2017-03-24 16:13 ` Matthew Wilcox [this message]
2017-03-27  5:01   ` [PATCH v3 5/7] zram: Convert to using memset_l Minchan Kim
2017-03-27  5:01     ` Minchan Kim
2017-03-24 16:13 ` [PATCH v3 6/7] sym53c8xx_2: Convert to use memset32 Matthew Wilcox
2017-03-24 16:13 ` [PATCH v3 7/7] vga: Optimise console scrolling Matthew Wilcox
2017-03-26  8:45   ` kbuild test robot
2017-03-26  9:53   ` kbuild test robot

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