Re: [PATCH 1/2] zsmalloc: do not scan for allocated objects in empty zspage

From: Alexey Romanov
Date: Mon Jun 26 2023 - 06:55:50 EST


On Sat, Jun 24, 2023 at 11:29:17AM +0900, Sergey Senozhatsky wrote:
> On (23/06/23 10:49), Alexey Romanov wrote:
> > > +static bool zspage_empty(struct zspage *zspage)
> > > +{
> > > + return get_zspage_inuse(zspage) == 0;
> > > +}
> > > +
> > > /**
> > > * zs_lookup_class_index() - Returns index of the zsmalloc &size_class
> > > * that hold objects of the provided size.
> > > @@ -1625,6 +1630,10 @@ static void migrate_zspage(struct zs_pool *pool, struct size_class *class,
> > > obj_idx++;
> > > record_obj(handle, free_obj);
> > > obj_free(class->size, used_obj);
> > > +
> > > + /* Stop if there are no more objects to migrate */
> > > + if (zspage_empty(get_zspage(s_page)))
> > > + break;
> > > }
> > >
> > > /* Remember last position in this iteration */
> > > --
> > > 2.41.0.162.gfafddb0af9-goog
> > >
> >
> > I think we can add similar check in zs_reclaim_page() function.
> > There we also scan zspage to find the allocated object.
>
> LRU was moved to zswap, so zs_reclaim_page() doesn't exist any longer
> (in linux-next).

Yeah, sorry. Just looking in current linux master.

--
Thank you,
Alexey