Re: [PATCH v2 2/2] vmscan: shrink_slab() require number of lru_pages, not page order

[KOSAKI Motohiro]

> >  	nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
> >  	if (nr_slab_pages0 > zone->min_slab_pages) {
> > +		unsigned long lru_pages = zone_reclaimable_pages(zone);
> > +
> >  		/*
> >  		 * shrink_slab() does not currently allow us to determine how
> >  		 * many pages were freed in this zone. So we take the current
> > @@ -2622,7 +2624,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
> >  		 * Note that shrink_slab will free memory on all zones and may
> >  		 * take a long time.
> >  		 */
> > -		while (shrink_slab(sc.nr_scanned, gfp_mask, order) &&
> > +		while (shrink_slab(sc.nr_scanned, gfp_mask, lru_pages) &&
> >  		       (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages >
> >  			nr_slab_pages0))
> >  			;
> 
> Wouldn't it be better to recalculate zone_reclaimable_pages() each time
> around the loop?  For example, shrink_icache_memory()->prune_icache()
> will remove pagecache from an inode if it hits the tail of the list. 
> This can change the number of reclaimable pages by squigabytes, but
> this code thinks nothing changed?

Ah, I missed this. incrementa patch is here.

thank you!