On Mon, Dec 13, 2021 at 03:30:41AM +0000, Matthew Wilcox wrote:
>
> When working on the vmcore conversion to iov_iter, I noticed we had a
> lot of places that construct a single kvec on the stack, and it seems a
> little wasteful. Adding an ITER_KADDR type makes the iov_iter a little
> easier to use.
>
> I included conversion of 9p to use ITER_KADDR so you can see whether you
> think it's worth doing.
I'd rather go for
static inline void kvec_single_range(int rw, void *buf, size_t len,
struct kvec *vec, struct iov_iter *i)
{
kvec->iov_base = buf;
kvec->iov_len = len;
iov_iter_kvec(i, rw, iov, 1, len);
}
to parallel the import_single_range(). You get more bloat in already
convoluted (to put it very mildly) macros in iov_iter.c than you save
on not declaring the local struct kvec variables in the users...
