On Fri, Jun 29, 2018 at 04:12:51PM +0800, Ming Lei wrote: > Only attempt to merge bio iff the ctx->rq_list isn't empty, because: > > 1) for high-performance SSD, most of times dispatch may succeed, then > there may be nothing left in ctx->rq_list, so don't try to merge over > sw queue if it is empty, then we can save one acquiring of ctx->lock > > 2) we can't expect good merge performance on per-cpu sw queue, and missing > one merge on sw queue won't be a big deal since tasks can be scheduled from > one CPU to another. Looks good, Reviewed-by: Christoph Hellwig <hch@xxxxxx>
