lib/sbitmap: kill 'depth' from sbitmap_word
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).
Remove 'depth' field from sbitmap_word, then the annotation of
____cacheline_aligned_in_smp for 'word' isn't needed any more.
Not see performance effect when running high parallel IOPS test on
null_blk.
This way saves us one cacheline(usually 64 words) per each sbitmap_word.
Cc: Martin Wilck <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Reviewed-by: John Garry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
2 files changed
