Re: [PATCH v4 4/4] fs/proc/vmcore: Use iov_iter_count()

[Matthew Wilcox]

On Fri, Mar 18, 2022 at 01:48:07PM +0000, David Laight wrote:
> For some definition of 'cleaner' :-)
> 
> iter->count is clearly a simple, cheap structure member lookup.
> OTOH iov_iter_count(iter) might be an expensive traversal of
> the vector (or worse).
> 
> So a quick read of the code by someone who isn't an expert
> in the iov functions leaves them wondering what is going on
> or having to spend time locating the definition ...

Thank you for having an opinion.  Al's opinion, as the iov_iter
maintainer, trumps yours.