On Mon Sep 8, 2025 at 8:31 PM JST, Alistair Popple wrote: > On 2025-09-07 at 20:54 +1000, Alice Ryhl <alicer...@google.com> wrote... >> On Wed, Aug 27, 2025 at 06:20:01PM +1000, Alistair Popple wrote: >> > From: Joel Fernandes <joelagn...@nvidia.com> >> > >> > A data structure that can be used to write across multiple slices which >> > may be out of order in memory. This lets SBuffer user correctly and >> > safely write out of memory order, without error-prone tracking of >> > pointers/offsets. >> > >> > let mut buf1 = [0u8; 3]; >> > let mut buf2 = [0u8; 5]; >> > let mut sbuffer = SBuffer::new([&mut buf1[..], &mut buf2[..]]); >> > >> > let data = b"hellowo"; >> > let result = sbuffer.write(data); >> > >> > An internal conversion of gsp.rs to use this resulted in a nice -ve delta: >> > gsp.rs: 37 insertions(+), 99 deletions(-) >> > >> > Co-developed-by: Alistair Popple <apop...@nvidia.com> >> > Signed-off-by: Alistair Popple <apop...@nvidia.com> >> > Signed-off-by: Joel Fernandes <joelagn...@nvidia.com> >> >> This seems like duplication of the logic in rust/kernel/iov_iter.rs [1]. > > Conceptually I guess there is some overlap. The thing that's different here > is we don't have any C version of the iovec struct or iov_iter, and AFAICT [1] > doesn't provide any way of creating one from within Rust code.
Yup, I was about to ask as well - I am not familiar with the C API, but how can we use it from Rust, using e.g. a pair of slices as the data source/destination? I see that `struct iovec` also has `__user` marker for its base, which hints to me that it is not designed to work with kernel data?
