On Fri, Nov 08, 2019 at 06:15:28PM +0800, Ming Lei wrote: > 64K PAGE_SIZE is popular on ARM64 or other ARCHs, and 64K has been big > enough to break some devices probably, so change the logic to split bio > if the only bvec's length is > SZ_4K instead of PAGE_SIZE. I don't think this makes sense as-is given that blk_queue_max_hw_sectors, blk_queue_max_segment_size and co all check for a minimum of PAGE_SIZE and warn otherwise, and blk_bio_segment_split uses PAGE_SIZE for its short cut as well. So I don't think this has been a problem in practice, and if it was this patch is not enough. So either we leave things as is, or we need to do a real audit for code using PAGE_SIZE as the minimum I/O granularity and replace it everywhere a well as updating the documentation. Which might be a good thing given that variable sized limits are weird.
