John, > Reading through this change, split_alignment appears similar in my > mind to limits->io_opt. io_opt is a hint which requests that the submitter does not issue any I/Os that are larger than this size. io_opt is smaller than or equal to the device's hard limit for I/O size. In the standards space it's described as "issuing an I/O larger than this value may incur a processing penalty". So not quite what you're looking for. However, we have chunk_sectors queue limit which is honored for splits. -- Martin K. Petersen Oracle Linux Engineering
