Re: [PATCH v2] mm: Optimise put_pages_list()

[Anthony Yznaga]

On 10/8/21 7:17 AM, Matthew Wilcox wrote:
> On Thu, Oct 07, 2021 at 04:35:54PM -0700, Andrew Morton wrote:
> > On Thu, 7 Oct 2021 21:55:21 +0100 Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> > > My first response is an appeal to authority -- release_pages() does
> > > this same thing.  Only it takes an array, constructs a list and passes
> > > that to put_unref_page_list().  So if that's slower (and lists _are_
> > > slower than arrays), we should have a put_unref_page_array().
> > And put_unref_page_list() does two passes across the list!
> >
> > <quietly sobs>
> >
> > Here is my beautiful release_pages(), as disrtibuted in linux-2.5.33:
> I think that looks much better!
>
> > I guess the current version is some commentary on the aging process?
> I blame the guy who sent cc59850ef940 to Linus back in 2011 ...
>
> I think Anthony was going to look into this and perhaps revert us to
> a pagevec_free() interface.


Sorry for not responding sooner.  I have some cycles so I'll take a look 
at this now.


Anthony