[PATCHv2 0/5] nvme-pci: iod optimisations

[Keith Busch]

On Tue, Aug 02, 2022 at 11:04:49AM +0530, Kanchan Joshi wrote:
> On Fri, Jul 29, 2022 at 09:28:46AM -0700, Keith Busch wrote:
> > From: Keith Busch <kbusch at kernel.org>
> > 
> > The series adjusts the struct nvme_iod fields for optimal sizing. The
> > end result on 64-bit arch removes 24 bytes, from 152 down to 128. We
> > typically allocate many thousands of these, and the cache aligned size
> > is a nice bonus.
> 
> Reviewed-by: Kanchan Joshi <joshi.k at samsung.com>
> 
> But would you like to reduce 8 more bytes by killing meta_dma field?
> This one:

Hm, yes, the iod's command is a local copy, so it is safe to do that. I suppose
we could use the same idea to remove 'first_dma' as well: it's a copy of either
dptr.prp2 or dptr.sgl.addr.