On 1/20/25 6:22 AM, Leon Romanovsky wrote:
On Fri, Jan 17, 2025 at 09:16:52PM +0000, David Howells wrote:
Hi,
I'd like to propose a discussion of two things: firstly, how might we improve
iov_iter and, secondly, would it be possible to replace scatterlists.
<...>
Rumour has it that John Hubbard may be working along similar lines, possibly
just in the area of bio_vecs and ITER_BVEC.
I do feel the need to apologize to Leon here, because I've been mostly MIA
ever we talked about this at LPC. Perhaps I'll actually be of some use in
2025. :)
[*] Second: Can we replace the uses of scatterlist with iov_iter and reduce
the number of iterator classes we have?
<...>
I would say yes to the questions.
Regarding rumors, I don't know, but Christoph, Jason and I are working towards
this goal. We proposed new DMA API which doesn't need scatterlists and allows
callers to implement their own data-structures.
See this "[PATCH v6 00/17] Provide a new two step DMA mapping API" series
https://lore.kernel.org/all/cover.1737106761.git.leon@xxxxxxxxxx
and its block layer followup "[RFC PATCH 0/7] Block and NMMe PCI use of
new DMA mapping API"
https://lore.kernel.org/all/cover.1730037261.git.leon@xxxxxxxxxx
Thanks
thanks,
--
John Hubbard
