[PATCH] drbd: use bitmap_weight()

From: Akinobu Mita
Date: Sun Mar 22 2015 - 03:31:48 EST


Use bitmap_weight to count the total number of bits set in bitmap.
This change just simplifies the code a bit.

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Cc: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
Cc: drbd-dev@xxxxxxxxxxxxxxxx
---
drivers/block/drbd/drbd_bitmap.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 434c77d..1e62c49 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -24,7 +24,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-#include <linux/bitops.h>
+#include <linux/bitmap.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <linux/drbd.h>
@@ -559,21 +559,19 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b)
unsigned long *p_addr;
unsigned long bits = 0;
unsigned long mask = (1UL << (b->bm_bits & BITS_PER_LONG_MASK)) -1;
- int idx, i, last_word;
+ int idx, last_word;

/* all but last page */
for (idx = 0; idx < b->bm_number_of_pages - 1; idx++) {
p_addr = __bm_map_pidx(b, idx);
- for (i = 0; i < LWPP; i++)
- bits += hweight_long(p_addr[i]);
+ bits += bitmap_weight(p_addr, PAGE_SIZE * BITS_PER_BYTE);
__bm_unmap(p_addr);
cond_resched();
}
/* last (or only) page */
last_word = ((b->bm_bits - 1) & BITS_PER_PAGE_MASK) >> LN2_BPL;
p_addr = __bm_map_pidx(b, idx);
- for (i = 0; i < last_word; i++)
- bits += hweight_long(p_addr[i]);
+ bits += bitmap_weight(p_addr, last_word * BITS_PER_LONG);
p_addr[last_word] &= cpu_to_lel(mask);
bits += hweight_long(p_addr[last_word]);
/* 32bit arch, may have an unused padding long */
@@ -1637,8 +1635,7 @@ int drbd_bm_e_weight(struct drbd_device *device, unsigned long enr)
int n = e-s;
p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, s));
bm = p_addr + MLPP(s);
- while (n--)
- count += hweight_long(*bm++);
+ count = bitmap_weight(bm, n * BITS_PER_LONG);
bm_unmap(p_addr);
} else {
drbd_err(device, "start offset (%d) too large in drbd_bm_e_weight\n", s);
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/