On Mon, 2019-07-22 at 08:22 +0300, Alexey Dobriyan wrote: > On Mon, Jul 22, 2019 at 08:08:33AM +0900, James Bottomley wrote: > > On Mon, 2019-07-22 at 00:52 +0300, Alexey Dobriyan wrote: > > > Each and every 1-byte access is aligned! > > > > The design idea of this is for parsing descriptors. We simply > > chunk up the describing structure using get_unaligned for > > everything. The reason is because a lot of these structures come > > with reserved areas which we may make use of later. If we're using > > get_unaligned for everything we can simply change a u8 to a u16 in > > the structure absorbing the reserved padding. With your change now > > I'd have to chase down every byte access and replace it with > > get_unaligned instead of simply changing the structure. > > > > What's the significant advantage of this change that compensates > > for the problems the above causes? > > HW descriptors have fixed endianness, you're supposed to use > get_unaligned_be32() and friends. Not if this is an internal descriptor format, which is what this is mostly used for. > For that matter, drivers/scsi/ has exactly 2 get_unaligned() calls > one of which can be changed to get_unaligned_be32(). You haven't answered the "what is the benefit of this change" question. I mean sure we can do it, but it won't make anything more efficient and it does help with the descriptor format to treat every structure field the same. James
