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[Qemu-devel] [PATCH v2 1/2] bitmap: get last word mask from nr directly
From: |
Wei Yang |
Subject: |
[Qemu-devel] [PATCH v2 1/2] bitmap: get last word mask from nr directly |
Date: |
Wed, 17 Jul 2019 15:11:13 +0800 |
The value left in nr is the number of bits for the last word, which
could be calculate the last word mask directly.
Remove the unnecessary size.
Signed-off-by: Wei Yang <address@hidden>
---
v2: refine bitmap_set_atomic too, suggested from Peter
---
util/bitmap.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/util/bitmap.c b/util/bitmap.c
index 1753ff7f5b..5b15249796 100644
--- a/util/bitmap.c
+++ b/util/bitmap.c
@@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned
long *bitmap1,
void bitmap_set(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
- const long size = start + nr;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
@@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr)
p++;
}
if (nr) {
- mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
*p |= mask_to_set;
}
}
@@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr)
void bitmap_set_atomic(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
- const long size = start + nr;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
@@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long
nr)
/* Last word */
if (nr) {
- mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
atomic_or(p, mask_to_set);
} else {
/* If we avoided the full barrier in atomic_or(), issue a
@@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long
nr)
void bitmap_clear(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
- const long size = start + nr;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
@@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr)
p++;
}
if (nr) {
- mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_clear &= BITMAP_LAST_WORD_MASK(nr);
*p &= ~mask_to_clear;
}
}
--
2.17.1