> 2025年7月16日 19:41，Christoph Hellwig <hch@xxxxxx> 写道： > > On Wed, Jul 16, 2025 at 07:39:18PM +0800, Coly Li wrote: >>>> For raid level 4/5/6 such split method might be problematic and hurt >>>> large read/write perforamnce. Because limits.max_hw_sectors are not >>>> always aligned to limits.io_opt size, the split bio won't be full >>>> stripes covered on all data disks, and will introduce extra read-in I/O. >>>> Even the bio's bi_sector is aligned to limits.io_opt size and large >>>> enough, the resulted split bio is not size-friendly to corresponding >>>> raid456 level. >>> >>> So why don't you set a sane max_hw_sectors value instead of duplicating >>> the splitting logic? >> >> Can you explain a bit more detail? In case I misunderstand you like I >> did with Kuai’s comments > > Just set the max_hw_sectors you want. Do you mean setting max_hw_sectors as (chunk_size * data_disks)?
