drbd: use bitmap_weight() helper, don't open code

Suggested by Akinobu Mita <akinobu.mita@gmail.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 8bdc34dbaedf..0dabc9b93725 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>
@@ -565,21 +565,19 @@ 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, BITS_PER_PAGE);
                 __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 */
@@ -1425,6 +1423,9 @@ static inline void bm_set_full_words_within_one_page(struct drbd_bitmap *b,
         int bits;
         int changed = 0;
         unsigned long *paddr = kmap_atomic(b->bm_pages[page_nr]);
+
+        /* I think it is more cache line friendly to hweight_long then set to ~0UL,
+         * than to first bitmap_weight() all words, then bitmap_fill() all words */
         for (i = first_word; i < last_word; i++) {
                 bits = hweight_long(paddr[i]);
                 paddr[i] = ~0UL;
@@ -1634,8 +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);