On 1/9/22 6:50 PM, Ming Lei wrote: > Only the last sbitmap_word can have different depth, and all the others > must have same depth of 1U << sb->shift, so not necessary to store it in > sbitmap_word, and it can be retrieved easily and efficiently by adding > one internal helper of __map_depth(sb, index). > > Not see performance effect when running iops test on null_blk. > > This way saves us one cacheline(usually 64 words) per each sbitmap_word. We probably want to kill the ____cacheline_aligned_in_smp from 'word' as well. -- Jens Axboe
