Re: [PATCH 03/25] mm, vmscan: Move LRU lists to node

From: Mel Gorman
Date: Mon Jun 15 2015 - 04:20:11 EST


On Thu, Jun 11, 2015 at 03:12:12PM +0800, Hillf Danton wrote:
> > @@ -774,6 +764,21 @@ typedef struct pglist_data {
> > ZONE_PADDING(_pad1_)
> > spinlock_t lru_lock;
> >
> > + /* Fields commonly accessed by the page reclaim scanner */
> > + struct lruvec lruvec;
> > +
> > + /* Evictions & activations on the inactive file list */
> > + atomic_long_t inactive_age;
> > +
> > + /*
> > + * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
> > + * this zone's LRU. Maintained by the pageout code.
> > + */
>
> The comment has to be updated.
>

Yes it does. Fixed.

> > + unsigned int inactive_ratio;
> > +
> > + unsigned long flags;
> > +
> > + ZONE_PADDING(_pad2_)
> > struct per_cpu_nodestat __percpu *per_cpu_nodestats;
> > atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
> > } pg_data_t;
> > @@ -1185,7 +1185,7 @@ struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
> > struct lruvec *lruvec;
> >
> > if (mem_cgroup_disabled()) {
> > - lruvec = &zone->lruvec;
> > + lruvec = zone_lruvec(zone);
> > goto out;
> > }
> >
> > @@ -1197,8 +1197,8 @@ out:
> > * we have to be prepared to initialize lruvec->zone here;
> > * and if offlined then reonlined, we need to reinitialize it.
> > */
> > - if (unlikely(lruvec->zone != zone))
> > - lruvec->zone = zone;
> > + if (unlikely(lruvec->pgdat != zone->zone_pgdat))
> > + lruvec->pgdat = zone->zone_pgdat;
>
> See below please.
>
> > return lruvec;
> > }
> >
> > @@ -1211,14 +1211,14 @@ out:
> > * and putback protocol: the LRU lock must be held, and the page must
> > * either be PageLRU() or the caller must have isolated/allocated it.
> > */
> > -struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
> > +struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgdat)
> > {
> > struct mem_cgroup_per_zone *mz;
> > struct mem_cgroup *memcg;
> > struct lruvec *lruvec;
> >
> > if (mem_cgroup_disabled()) {
> > - lruvec = &zone->lruvec;
> > + lruvec = &pgdat->lruvec;
> > goto out;
> > }
> >
> > @@ -1238,8 +1238,8 @@ out:
> > * we have to be prepared to initialize lruvec->zone here;
> > * and if offlined then reonlined, we need to reinitialize it.
> > */
> > - if (unlikely(lruvec->zone != zone))
> > - lruvec->zone = zone;
> > + if (unlikely(lruvec->pgdat != pgdat))
> > + lruvec->pgdat = pgdat;
>
> Given &pgdat->lruvec, we no longer need(or are able) to set lruvec->pgdat.
>

I do not understand your comment. This is setting a mapping between lruvec
and pgdat, not the other way around. It's a straight-forward conversion
of zone to pgdat.

--
Mel Gorman
SUSE Labs
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