On Sat, Apr 25 2020 at 3:53am -0400, Christoph Hellwig <hch@xxxxxx> wrote: > Call blk_mq_make_request when no ->make_request_fn is set. This is > safe now that blk_alloc_queue always sets up the pointer for make_request > based drivers. This avoids an indirect call in the blk-mq driver I/O > fast path, which is rather expensive due to spectre mitigations. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Makes me cringe thinking about all the indirect calls sprinkled throughout DM... Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx>
