Message ID | 20110310140341.CFAFE1336E@gandalf.localdomain |
---|---|
State | New |
Headers | show |
On Thu, Mar 10, 2011 at 11:03 PM, Michael Tokarev <mjt@tls.msk.ru> wrote: > qemu now has generic bitmap functions, > so don't redefine them in sheepdog.c, > use common header instead. A small cleanup. > > Here's only one function which is actually > used in sheepdog and gets replaced with > a generic one (simplified): > > - static inline int test_bit(int nr, const volatile unsigned long *addr) > + static inline int test_bit(int nr, const unsigned long *addr) > { > - return ((1UL << (nr % BITS_PER_LONG)) > & ((unsigned long*)addr)[nr / BITS_PER_LONG])) != 0; > + return 1UL & (addr[nr / BITS_PER_LONG] >> (nr & (BITS_PER_LONG-1))); > } > > The body is equivalent, but the argument is not: there's > "volatile" in there. Why it is used for - I'm not sure. > > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Looks good. Thanks! Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
On Thu, Mar 10, 2011 at 05:03:41PM +0300, Michael Tokarev wrote: > qemu now has generic bitmap functions, > so don't redefine them in sheepdog.c, > use common header instead. A small cleanup. > > Here's only one function which is actually > used in sheepdog and gets replaced with > a generic one (simplified): > > - static inline int test_bit(int nr, const volatile unsigned long *addr) > + static inline int test_bit(int nr, const unsigned long *addr) > { > - return ((1UL << (nr % BITS_PER_LONG)) > & ((unsigned long*)addr)[nr / BITS_PER_LONG])) != 0; > + return 1UL & (addr[nr / BITS_PER_LONG] >> (nr & (BITS_PER_LONG-1))); > } > > The body is equivalent, but the argument is not: there's > "volatile" in there. Why it is used for - I'm not sure. > > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Thanks, applied. > diff --git a/block/sheepdog.c b/block/sheepdog.c > index a54e0de..98946d7 100644 > --- a/block/sheepdog.c > +++ b/block/sheepdog.c > @@ -13,6 +13,7 @@ > #include "qemu-error.h" > #include "qemu_socket.h" > #include "block_int.h" > +#include "bitops.h" > > #define SD_PROTO_VER 0x01 > > @@ -1829,20 +1830,6 @@ static int sd_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) > return 0; > } > > -#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) > -#define BITS_PER_BYTE 8 > -#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) > -#define DECLARE_BITMAP(name,bits) \ > - unsigned long name[BITS_TO_LONGS(bits)] > - > -#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long)) > - > -static inline int test_bit(unsigned int nr, const unsigned long *addr) > -{ > - return ((1UL << (nr % BITS_PER_LONG)) & > - (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; > -} > - > static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) > { > BDRVSheepdogState *s = bs->opaque; > >
diff --git a/block/sheepdog.c b/block/sheepdog.c index a54e0de..98946d7 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -13,6 +13,7 @@ #include "qemu-error.h" #include "qemu_socket.h" #include "block_int.h" +#include "bitops.h" #define SD_PROTO_VER 0x01 @@ -1829,20 +1830,6 @@ static int sd_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) return 0; } -#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) -#define BITS_PER_BYTE 8 -#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) -#define DECLARE_BITMAP(name,bits) \ - unsigned long name[BITS_TO_LONGS(bits)] - -#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long)) - -static inline int test_bit(unsigned int nr, const unsigned long *addr) -{ - return ((1UL << (nr % BITS_PER_LONG)) & - (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; -} - static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) { BDRVSheepdogState *s = bs->opaque;
qemu now has generic bitmap functions, so don't redefine them in sheepdog.c, use common header instead. A small cleanup. Here's only one function which is actually used in sheepdog and gets replaced with a generic one (simplified): - static inline int test_bit(int nr, const volatile unsigned long *addr) + static inline int test_bit(int nr, const unsigned long *addr) { - return ((1UL << (nr % BITS_PER_LONG)) & ((unsigned long*)addr)[nr / BITS_PER_LONG])) != 0; + return 1UL & (addr[nr / BITS_PER_LONG] >> (nr & (BITS_PER_LONG-1))); } The body is equivalent, but the argument is not: there's "volatile" in there. Why it is used for - I'm not sure. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>