On 11/24/18 8:17 AM, Emilio G. Cota wrote:
On Thu, Nov 22, 2018 at 15:20:25 +0800, guangrong.xiao@xxxxxxxxx wrote:+static uint64_t get_free_request_bitmap(Threads *threads, ThreadLocal *thread) +{ + uint64_t request_fill_bitmap, request_done_bitmap, result_bitmap; + + request_fill_bitmap = atomic_rcu_read(&thread->request_fill_bitmap); + request_done_bitmap = atomic_rcu_read(&thread->request_done_bitmap); + bitmap_xor(&result_bitmap, &request_fill_bitmap, &request_done_bitmap, + threads->thread_requests_nr);This is not wrong, but it's a big ugly. Instead, I would: - Introduce bitmap_xor_atomic in a previous patch - Use bitmap_xor_atomic here, getting rid of the rcu reads
Hmm, however, we do not need atomic xor operation here... that should be slower than just two READ_ONCE calls.
