Re: [PATCH 05/10] mm: remove LRU balancing effect of temporary page isolation

[Rik van Riel <riel@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1326 bytes --]

On Mon, 2016-06-06 at 18:15 -0400, Johannes Weiner wrote:
> On Mon, Jun 06, 2016 at 05:56:09PM -0400, Rik van Riel wrote:
> > 
> > On Mon, 2016-06-06 at 15:48 -0400, Johannes Weiner wrote:
> > > 
> > >  
> > > +void lru_cache_putback(struct page *page)
> > > +{
> > > +	struct pagevec *pvec = &get_cpu_var(lru_putback_pvec);
> > > +
> > > +	get_page(page);
> > > +	if (!pagevec_space(pvec))
> > > +		__pagevec_lru_add(pvec, false);
> > > +	pagevec_add(pvec, page);
> > > +	put_cpu_var(lru_putback_pvec);
> > > +}
> > > 
> > Wait a moment.
> > 
> > So now we have a putback_lru_page, which does adjust
> > the statistics, and an lru_cache_putback which does
> > not?
> > 
> > This function could use a name that is not as similar
> > to its counterpart :)
> lru_cache_add() and lru_cache_putback() are the two sibling
> functions,
> where the first influences the LRU balance and the second one
> doesn't.
> 
> The last hunk in the patch (obscured by showing the label instead of
> the function name as context) updates putback_lru_page() from using
> lru_cache_add() to using lru_cache_putback().
> 
> Does that make sense?

That means the page reclaim does not update the
"rotated" statistics.  That seems undesirable,
no?  Am I overlooking something?


-- 
All Rights Reversed.


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 473 bytes --]