On Wed, Oct 08 2014 at 6:12pm -0400, Jens Axboe <ax...@kernel.dk> wrote:
> On 10/08/2014 04:05 PM, Mike Snitzer wrote: > > The math in both blk_stack_limits() and queue_limit_alignment_offset() > > assume that a block device's io_min (aka minimum_io_size) is always a > > power-of-2. Fix the math such that it works for non-power-of-2 io_min. > > > > This issue (of alignment_offset != 0) became apparent when testing > > dm-thinp with a thinp blocksize that matches a RAID6 stripesize of > > 1280K. Commit fdfb4c8c1 ("dm thin: set minimum_io_size to pool's data > > block size") unlocked the potential for alignment_offset != 0 due to > > the dm-thin-pool's io_min possibly being a non-power-of-2. > > Well that sucks, AND with a mask is considerably cheaper than a MOD... Yeah, certainly does suck (please note v2 that I just sent). The MODs shouldn't kill us, these functions aren't called in any real hot path. A storm at boot maybe.. or SCSI rescan but... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/