Olaf Hering
2012-Jan-30 12:12 UTC
[PATCH] tools/libxc: remove volatile keyword for bitmap operations
# HG changeset patch
# User Olaf Hering <olaf@aepfle.de>
# Date 1327925537 -3600
# Node ID 686f053d460da35f26b42b74e2ef41b6aceb5711
# Parent 4374739bd1428aead1c7f49beac6a28031c8d20b
tools/libxc: remove volatile keyword for bitmap operations
All bitmaps maintained by xc_bitops.h are used in single threaded
applications. So nothing will change the bitmaps content, adding
volatile adds just unneeded memory reloads.
xenpaging uses bitmaps alot and using non-volatile versions will slightly
improve performance.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
diff -r 4374739bd142 -r 686f053d460d tools/libxc/xc_bitops.h
--- a/tools/libxc/xc_bitops.h
+++ b/tools/libxc/xc_bitops.h
@@ -31,29 +31,29 @@ static inline void bitmap_clear(unsigned
memset(addr, 0, bitmap_size(nr_bits));
}
-static inline int test_bit(int nr, volatile unsigned long *addr)
+static inline int test_bit(int nr, unsigned long *addr)
{
return (BITMAP_ENTRY(nr, addr) >> BITMAP_SHIFT(nr)) & 1;
}
-static inline void clear_bit(int nr, volatile unsigned long *addr)
+static inline void clear_bit(int nr, unsigned long *addr)
{
BITMAP_ENTRY(nr, addr) &= ~(1UL << BITMAP_SHIFT(nr));
}
-static inline void set_bit(int nr, volatile unsigned long *addr)
+static inline void set_bit(int nr, unsigned long *addr)
{
BITMAP_ENTRY(nr, addr) |= (1UL << BITMAP_SHIFT(nr));
}
-static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
+static inline int test_and_clear_bit(int nr, unsigned long *addr)
{
int oldbit = test_bit(nr, addr);
clear_bit(nr, addr);
return oldbit;
}
-static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
+static inline int test_and_set_bit(int nr, unsigned long *addr)
{
int oldbit = test_bit(nr, addr);
set_bit(nr, addr);