Re: [PATCH v4 13/16] mm: Pass pvec directly to find_get_entries

[Matthew Wilcox]

On Sat, Nov 14, 2020 at 11:21:33AM +0100, Christoph Hellwig wrote:
> On Thu, Nov 12, 2020 at 09:26:38PM +0000, Matthew Wilcox (Oracle) wrote:
> > +	pvec->nr = ret;
> >  	return ret;
> 
> Do we need to return the number of found entries in addition to storing
> it in the pagevec?

We really only need a bool -- is pvec->nr zero or not.  But we have the
number calculated so we may as well return it.  All the current find_*()
behave this way and I haven't seen enough reason to change it yet.
Making it return void just makes the callers uglier.  I have a batch of
patches to do something similar for find_get_pages / find_get_pages_range
/ pagevec_lookup / pagevec_lookup_range, but I don't need them for the
THP patchset, so I haven't sent them yet.