Re: [PATCH v2 2/3] iov_iter: introduce iov_iter_pin_user_pages*() routines

[John Hubbard <jhubbard@xxxxxxxxxx>]

On 8/29/20 7:58 AM, Christoph Hellwig wrote:
> On Sat, Aug 29, 2020 at 01:08:52AM -0700, John Hubbard wrote:
...
> > @@ -1280,7 +1281,11 @@ static inline ssize_t __pipe_get_pages(struct iov_iter *i,
> >   	maxsize = n;
> >   	n += *start;
> >   	while (n > 0) {
> > -		get_page(*pages++ = pipe->bufs[iter_head & p_mask].page);
> > +		if (use_pup)
> > +			pin_user_page(*pages++ = pipe->bufs[iter_head & p_mask].page);
> > +		else
> > +			get_page(*pages++ = pipe->bufs[iter_head & p_mask].page);
>
> Maybe this would become a little more readable with a local variable
> and a little more verbosity:
>
> 		struct page *page = pipe->bufs[iter_head & p_mask].page;
>
> 		if (use_pup)
> 			pin_user_page(page);
> 		else
> 			get_page(page);
>
> 		*pages++ = page;

Yes, that is cleaner, I'll change to that, thanks.

thanks,
--
John Hubbard
NVIDIA