On 23/11/2015 10:55, Fam Zheng wrote: >>> Why? I think bitmap_set is a better match with bitmap_new below. >> >> set_bit() is quicker than bitmap_set() if you only set one bit. > > How much quicker is it? This doesn't sound convincing enough for me to lose > the > readability.
Substantially. It's also documented: /* * Also the following operations apply to bitmaps. * * set_bit(bit, addr) *addr |= bit * clear_bit(bit, addr) *addr &= ~bit * change_bit(bit, addr) *addr ^= bit * test_bit(bit, addr) Is bit set in *addr? * test_and_set_bit(bit, addr) Set bit and return old value * test_and_clear_bit(bit, addr) Clear bit and return old value * test_and_change_bit(bit, addr) Change bit and return old value * find_first_zero_bit(addr, nbits) Position first zero bit in *addr * find_first_bit(addr, nbits) Position first set bit in *addr * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit */ Paolo
