On Mon, Aug 21, 2017 at 12:27:30PM +0300, Adrian Hunter wrote: > We need to start with a legacy API because people want to backport CQ to > earlier kernels (we really need to get features upstream more quickly), but > blk-mq has been evolving a lot (e.g. elevator support), so backporters face > having either something quite different from upstream or trying to backport > great chunks of the block layer. Hell no - the point of Linux mainline development is to move forward. We'll need to do the right thing for long term Linux development FIRST and then worry about backporting SECOND. Stop thinking about all kernels while you wear your mainline kernel developer hat. Yes, occasionally we can do smaller amount of reordering to keep a small fix first for stable backports, but not to this extent of using obsolete infrastructure and making an already messy driver worse just to please backports to long obsolete kernels.
