/* Check that we have not crossed a zone boundary. */
if (unlikely(page_zone_id(cursor_page) != zone_id))
continue;
+
+ /*
+ * If we don't have enough swap space, reclaiming of
+ * anon page which don't already have a swap slot is
+ * pointless.
+ */
+ if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
+ !PageSwapCache(cursor_page))
+ continue;
+
if (__isolate_lru_page(cursor_page, mode, file) == 0) {
list_move(&cursor_page->lru, dst);
mem_cgroup_del_lru(cursor_page);
return ret;
}
+/*
+ * Are there way too many processes in the direct reclaim path already?
+ */
+static int too_many_isolated(struct zone *zone, int file,
+ struct scan_control *sc)
+{
+ unsigned long inactive, isolated;
+
+ if (current_is_kswapd())
+ return 0;
+
+ if (!scanning_global_lru(sc))
+ return 0;
+
+ if (file) {
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+ isolated = zone_page_state(zone, NR_ISOLATED_FILE);
+ } else {
+ inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+ isolated = zone_page_state(zone, NR_ISOLATED_ANON);
+ }
+
+ return isolated > inactive;
+}
+
/*
* shrink_inactive_list() is a helper for shrink_zone(). It returns the number
* of reclaimed pages
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
int lumpy_reclaim = 0;
+ while (unlikely(too_many_isolated(zone, file, sc))) {
+ congestion_wait(WRITE, HZ/10);
+
+ /* We are about to die and free our memory. Return now. */
+ if (fatal_signal_pending(current))
+ return SWAP_CLUSTER_MAX;
+ }
+
/*
* If we need a large contiguous chunk of memory, or have
* trouble getting a small set of contiguous pages, we
unsigned long nr_active;
unsigned int count[NR_LRU_LISTS] = { 0, };
int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
+ unsigned long nr_anon;
+ unsigned long nr_file;
nr_taken = sc->isolate_pages(sc->swap_cluster_max,
&page_list, &nr_scan, sc->order, mode,
zone, sc->mem_cgroup, 0, file);
+
+ if (scanning_global_lru(sc)) {
+ zone->pages_scanned += nr_scan;
+ if (current_is_kswapd())
+ __count_zone_vm_events(PGSCAN_KSWAPD, zone,
+ nr_scan);
+ else
+ __count_zone_vm_events(PGSCAN_DIRECT, zone,
+ nr_scan);
+ }
+
+ if (nr_taken == 0)
+ goto done;
+
nr_active = clear_active_flags(&page_list, count);
__count_vm_events(PGDEACTIVATE, nr_active);
__mod_zone_page_state(zone, NR_INACTIVE_ANON,
-count[LRU_INACTIVE_ANON]);
- if (scanning_global_lru(sc))
- zone->pages_scanned += nr_scan;
+ nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];
+ nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon);
+ __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file);
reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON];
reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON];
}
nr_reclaimed += nr_freed;
+
local_irq_disable();
- if (current_is_kswapd()) {
- __count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scan);
+ if (current_is_kswapd())
__count_vm_events(KSWAPD_STEAL, nr_freed);
- } else if (scanning_global_lru(sc))
- __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scan);
-
__count_zone_vm_events(PGSTEAL, zone, nr_freed);
- if (nr_taken == 0)
- goto done;
-
spin_lock(&zone->lru_lock);
/*
* Put back any unfreeable pages.
SetPageLRU(page);
lru = page_lru(page);
add_page_to_lru_list(zone, page, lru);
- if (PageActive(page)) {
- int file = !!page_is_file_cache(page);
+ if (is_active_lru(lru)) {
+ int file = !!is_file_lru(lru);
reclaim_stat->recent_rotated[file]++;
}
if (!pagevec_add(&pvec, page)) {
spin_lock_irq(&zone->lru_lock);
}
}
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);
+ __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);
+
} while (nr_scanned < max_scan);
- spin_unlock(&zone->lru_lock);
+
done:
- local_irq_enable();
+ spin_unlock_irq(&zone->lru_lock);
pagevec_release(&pvec);
return nr_reclaimed;
}
while (!list_empty(list)) {
page = lru_to_page(list);
- prefetchw_prev_lru_page(page, list, flags);
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
- VM_BUG_ON(!PageActive(page));
- if (!is_active_lru(lru))
- ClearPageActive(page); /* we are de-activating */
-
list_move(&page->lru, &zone->lru[lru].list);
mem_cgroup_add_lru_list(page, lru);
pgmoved++;
__mod_zone_page_state(zone, NR_ACTIVE_FILE, -nr_taken);
else
__mod_zone_page_state(zone, NR_ACTIVE_ANON, -nr_taken);
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
spin_unlock_irq(&zone->lru_lock);
while (!list_empty(&l_hold)) {
}
}
+ ClearPageActive(page); /* we are de-activating */
list_add(&page->lru, &l_inactive);
}
LRU_ACTIVE + file * LRU_FILE);
move_active_pages_to_lru(zone, &l_inactive,
LRU_BASE + file * LRU_FILE);
-
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&zone->lru_lock);
}
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_lru_pages(zone);
+ lru_pages += zone_reclaimable_pages(zone);
}
}
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
- lru_pages += zone_lru_pages(zone);
+ lru_pages += zone_reclaimable_pages(zone);
}
/*
if (zone_is_all_unreclaimable(zone))
continue;
if (nr_slab == 0 && zone->pages_scanned >=
- (zone_lru_pages(zone) * 6))
+ (zone_reclaimable_pages(zone) * 6))
zone_set_flag(zone,
ZONE_ALL_UNRECLAIMABLE);
/*
wake_up_interruptible(&pgdat->kswapd_wait);
}
-unsigned long global_lru_pages(void)
+/*
+ * The reclaimable count would be mostly accurate.
+ * The less reclaimable pages may be
+ * - mlocked pages, which will be moved to unevictable list when encountered
+ * - mapped pages, which may require several travels to be reclaimed
+ * - dirty pages, which is not "instantly" reclaimable
+ */
+unsigned long global_reclaimable_pages(void)
+{
+ int nr;
+
+ nr = global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_FILE);
+
+ if (nr_swap_pages > 0)
+ nr += global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_ANON);
+
+ return nr;
+}
+
+unsigned long zone_reclaimable_pages(struct zone *zone)
{
- return global_page_state(NR_ACTIVE_ANON)
- + global_page_state(NR_ACTIVE_FILE)
- + global_page_state(NR_INACTIVE_ANON)
- + global_page_state(NR_INACTIVE_FILE);
+ int nr;
+
+ nr = zone_page_state(zone, NR_ACTIVE_FILE) +
+ zone_page_state(zone, NR_INACTIVE_FILE);
+
+ if (nr_swap_pages > 0)
+ nr += zone_page_state(zone, NR_ACTIVE_ANON) +
+ zone_page_state(zone, NR_INACTIVE_ANON);
+
+ return nr;
}
#ifdef CONFIG_HIBERNATION
current->reclaim_state = &reclaim_state;
- lru_pages = global_lru_pages();
+ lru_pages = global_reclaimable_pages();
nr_slab = global_page_state(NR_SLAB_RECLAIMABLE);
/* If slab caches are huge, it's better to hit them first */
while (nr_slab >= lru_pages) {
reclaim_state.reclaimed_slab = 0;
shrink_slab(sc.nr_scanned, sc.gfp_mask,
- global_lru_pages());
+ global_reclaimable_pages());
sc.nr_reclaimed += reclaim_state.reclaimed_slab;
if (sc.nr_reclaimed >= nr_pages)
goto out;
if (!sc.nr_reclaimed) {
do {
reclaim_state.reclaimed_slab = 0;
- shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
+ shrink_slab(nr_pages, sc.gfp_mask,
+ global_reclaimable_pages());
sc.nr_reclaimed += reclaim_state.reclaimed_slab;
} while (sc.nr_reclaimed < nr_pages &&
reclaim_state.reclaimed_slab > 0);