Re: [RFC][PATCHv3 2/7] zsmalloc: partial page ordering within a fullness_list

Minchan Kim
2015-06-30T00:43:06Z

On Tue, Jun 30, 2015 at 08:41:24AM +0900, Sergey Senozhatsky wrote:
> Hello,
>
> Sorry for long reply.
>
> On (06/29/15 15:52), Minchan Kim wrote:
> [..]
> > > head = &class->fullness_list[fullness];
> > > - if (*head)
> > > - list_add_tail(&page->lru, &(*head)->lru);
> > > + if (*head) {
> > > + /*
> > > + * We want to see more ZS_FULL pages and less almost
> > > + * empty/full. Put pages with higher ->inuse first.
> > > + */
> > > + if (page->inuse < (*head)->inuse)
> > > + list_add_tail(&page->lru, &(*head)->lru);
> > > + else
> > > + list_add(&page->lru, &(*head)->lru);
> > > + }
> >
> > >
> > > *head = page;
> >
> > Why do you want to always put @page in the head?
> > How about this?
>
>
> Yeah, right. Looks OK to me. How do we want to handle it? Do you want
> to submit it with Suggested-by: ss (I'm fine) or you want me to submit
> it later today with Suggested-by: Minchan Kim?

Hi Sergey,

Thanks for considering the credit.
However, it was just review so no need my sign. :)

I really appreciate your good works.
Thanks.

>
> -ss
>
> > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> > index e8cb31c..1c5fde9 100644
> > --- a/mm/zsmalloc.c
> > +++ b/mm/zsmalloc.c
> > @@ -658,21 +658,25 @@ static void insert_zspage(struct page *page, struct size_class *class,
> > if (fullness >= _ZS_NR_FULLNESS_GROUPS)
> > return;
> >
> > + zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ?
> > + CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1);
> > +
> > head = &class->fullness_list[fullness];
> > - if (*head) {
> > - /*
> > - * We want to see more ZS_FULL pages and less almost
> > - * empty/full. Put pages with higher ->inuse first.
> > - */
> > - if (page->inuse < (*head)->inuse)
> > - list_add_tail(&page->lru, &(*head)->lru);
> > - else
> > - list_add(&page->lru, &(*head)->lru);
> > + if (!*head) {
> > + *head = page;
> > + return;
> > }
> >
> > - *head = page;
> > - zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ?
> > - CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1);
> > + /*
> > + * We want to see more ZS_FULL pages and less almost
> > + * empty/full. Put pages with higher ->inuse first.
> > + */
> > + list_add_tail(&page->lru, &(*head)->lru);
> > + if (page->inuse >= (*head)->inuse)
> > + *head = page;
> > }

--
Kind regards,
Minchan Kim