unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
unsigned long *scanned, int order, int mode,
struct zone *z, struct mem_cgroup *mem_cont,
- int active);
+ int active, int file);
};
#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
*
* returns 0 on success, -ve errno on failure.
*/
-int __isolate_lru_page(struct page *page, int mode)
+int __isolate_lru_page(struct page *page, int mode, int file)
{
int ret = -EINVAL;
if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
return ret;
+ if (mode != ISOLATE_BOTH && (!page_is_file_cache(page) != !file))
+ return ret;
+
ret = -EBUSY;
if (likely(get_page_unless_zero(page))) {
/*
* @scanned: The number of pages that were scanned.
* @order: The caller's attempted allocation order
* @mode: One of the LRU isolation modes
+ * @file: True [1] if isolating file [!anon] pages
*
* returns how many pages were moved onto *@dst.
*/
static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
struct list_head *src, struct list_head *dst,
- unsigned long *scanned, int order, int mode)
+ unsigned long *scanned, int order, int mode, int file)
{
unsigned long nr_taken = 0;
unsigned long scan;
VM_BUG_ON(!PageLRU(page));
- switch (__isolate_lru_page(page, mode)) {
+ switch (__isolate_lru_page(page, mode, file)) {
case 0:
list_move(&page->lru, dst);
nr_taken++;
break;
cursor_page = pfn_to_page(pfn);
+
/* Check that we have not crossed a zone boundary. */
if (unlikely(page_zone_id(cursor_page) != zone_id))
continue;
- switch (__isolate_lru_page(cursor_page, mode)) {
+ switch (__isolate_lru_page(cursor_page, mode, file)) {
case 0:
list_move(&cursor_page->lru, dst);
nr_taken++;
unsigned long *scanned, int order,
int mode, struct zone *z,
struct mem_cgroup *mem_cont,
- int active)
+ int active, int file)
{
+ int lru = LRU_BASE;
if (active)
- return isolate_lru_pages(nr, &z->lru[LRU_ACTIVE].list, dst,
- scanned, order, mode);
- else
- return isolate_lru_pages(nr, &z->lru[LRU_INACTIVE].list, dst,
- scanned, order, mode);
+ lru += LRU_ACTIVE;
+ if (file)
+ lru += LRU_FILE;
+ return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
+ mode, !!file);
}
/*
* clear_active_flags() is a helper for shrink_active_list(), clearing
* any active bits from the pages in the list.
*/
-static unsigned long clear_active_flags(struct list_head *page_list)
+static unsigned long clear_active_flags(struct list_head *page_list,
+ unsigned int *count)
{
int nr_active = 0;
+ int lru;
struct page *page;
- list_for_each_entry(page, page_list, lru)
+ list_for_each_entry(page, page_list, lru) {
+ lru = page_is_file_cache(page);
if (PageActive(page)) {
+ lru += LRU_ACTIVE;
ClearPageActive(page);
nr_active++;
}
+ count[lru]++;
+ }
return nr_active;
}
spin_lock_irq(&zone->lru_lock);
if (PageLRU(page) && get_page_unless_zero(page)) {
+ int lru = LRU_BASE;
ret = 0;
ClearPageLRU(page);
- if (PageActive(page))
- del_page_from_active_list(zone, page);
- else
- del_page_from_inactive_list(zone, page);
+
+ lru += page_is_file_cache(page) + !!PageActive(page);
+ del_page_from_lru_list(zone, page, lru);
}
spin_unlock_irq(&zone->lru_lock);
}
* of reclaimed pages
*/
static unsigned long shrink_inactive_list(unsigned long max_scan,
- struct zone *zone, struct scan_control *sc)
+ struct zone *zone, struct scan_control *sc, int file)
{
LIST_HEAD(page_list);
struct pagevec pvec;
unsigned long nr_scan;
unsigned long nr_freed;
unsigned long nr_active;
+ unsigned int count[NR_LRU_LISTS] = { 0, };
+ int mode = (sc->order > PAGE_ALLOC_COSTLY_ORDER) ?
+ ISOLATE_BOTH : ISOLATE_INACTIVE;
nr_taken = sc->isolate_pages(sc->swap_cluster_max,
- &page_list, &nr_scan, sc->order,
- (sc->order > PAGE_ALLOC_COSTLY_ORDER)?
- ISOLATE_BOTH : ISOLATE_INACTIVE,
- zone, sc->mem_cgroup, 0);
- nr_active = clear_active_flags(&page_list);
+ &page_list, &nr_scan, sc->order, mode,
+ zone, sc->mem_cgroup, 0, file);
+ nr_active = clear_active_flags(&page_list, count);
__count_vm_events(PGDEACTIVATE, nr_active);
- __mod_zone_page_state(zone, NR_ACTIVE, -nr_active);
- __mod_zone_page_state(zone, NR_INACTIVE,
- -(nr_taken - nr_active));
- if (scan_global_lru(sc))
+ __mod_zone_page_state(zone, NR_ACTIVE_FILE,
+ -count[LRU_ACTIVE_FILE]);
+ __mod_zone_page_state(zone, NR_INACTIVE_FILE,
+ -count[LRU_INACTIVE_FILE]);
+ __mod_zone_page_state(zone, NR_ACTIVE_ANON,
+ -count[LRU_ACTIVE_ANON]);
+ __mod_zone_page_state(zone, NR_INACTIVE_ANON,
+ -count[LRU_INACTIVE_ANON]);
+
+ if (scan_global_lru(sc)) {
zone->pages_scanned += nr_scan;
+ zone->recent_scanned[0] += count[LRU_INACTIVE_ANON];
+ zone->recent_scanned[0] += count[LRU_ACTIVE_ANON];
+ zone->recent_scanned[1] += count[LRU_INACTIVE_FILE];
+ zone->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+ }
spin_unlock_irq(&zone->lru_lock);
nr_scanned += nr_scan;
* The attempt at page out may have made some
* of the pages active, mark them inactive again.
*/
- nr_active = clear_active_flags(&page_list);
+ nr_active = clear_active_flags(&page_list, count);
count_vm_events(PGDEACTIVATE, nr_active);
nr_freed += shrink_page_list(&page_list, sc,
SetPageLRU(page);
list_del(&page->lru);
add_page_to_lru_list(zone, page, page_lru(page));
+ if (PageActive(page) && scan_global_lru(sc)) {
+ int file = !!page_is_file_cache(page);
+ zone->recent_rotated[file]++;
+ }
if (!pagevec_add(&pvec, page)) {
spin_unlock_irq(&zone->lru_lock);
__pagevec_release(&pvec);
static inline int zone_is_near_oom(struct zone *zone)
{
- return zone->pages_scanned >= (zone_page_state(zone, NR_ACTIVE)
- + zone_page_state(zone, NR_INACTIVE))*3;
-}
-
-/*
- * Determine we should try to reclaim mapped pages.
- * This is called only when sc->mem_cgroup is NULL.
- */
-static int calc_reclaim_mapped(struct scan_control *sc, struct zone *zone,
- int priority)
-{
- long mapped_ratio;
- long distress;
- long swap_tendency;
- long imbalance;
- int reclaim_mapped = 0;
- int prev_priority;
-
- if (scan_global_lru(sc) && zone_is_near_oom(zone))
- return 1;
- /*
- * `distress' is a measure of how much trouble we're having
- * reclaiming pages. 0 -> no problems. 100 -> great trouble.
- */
- if (scan_global_lru(sc))
- prev_priority = zone->prev_priority;
- else
- prev_priority = mem_cgroup_get_reclaim_priority(sc->mem_cgroup);
-
- distress = 100 >> min(prev_priority, priority);
-
- /*
- * The point of this algorithm is to decide when to start
- * reclaiming mapped memory instead of just pagecache. Work out
- * how much memory
- * is mapped.
- */
- if (scan_global_lru(sc))
- mapped_ratio = ((global_page_state(NR_FILE_MAPPED) +
- global_page_state(NR_ANON_PAGES)) * 100) /
- vm_total_pages;
- else
- mapped_ratio = mem_cgroup_calc_mapped_ratio(sc->mem_cgroup);
-
- /*
- * Now decide how much we really want to unmap some pages. The
- * mapped ratio is downgraded - just because there's a lot of
- * mapped memory doesn't necessarily mean that page reclaim
- * isn't succeeding.
- *
- * The distress ratio is important - we don't want to start
- * going oom.
- *
- * A 100% value of vm_swappiness overrides this algorithm
- * altogether.
- */
- swap_tendency = mapped_ratio / 2 + distress + sc->swappiness;
-
- /*
- * If there's huge imbalance between active and inactive
- * (think active 100 times larger than inactive) we should
- * become more permissive, or the system will take too much
- * cpu before it start swapping during memory pressure.
- * Distress is about avoiding early-oom, this is about
- * making swappiness graceful despite setting it to low
- * values.
- *
- * Avoid div by zero with nr_inactive+1, and max resulting
- * value is vm_total_pages.
- */
- if (scan_global_lru(sc)) {
- imbalance = zone_page_state(zone, NR_ACTIVE);
- imbalance /= zone_page_state(zone, NR_INACTIVE) + 1;
- } else
- imbalance = mem_cgroup_reclaim_imbalance(sc->mem_cgroup);
-
- /*
- * Reduce the effect of imbalance if swappiness is low,
- * this means for a swappiness very low, the imbalance
- * must be much higher than 100 for this logic to make
- * the difference.
- *
- * Max temporary value is vm_total_pages*100.
- */
- imbalance *= (vm_swappiness + 1);
- imbalance /= 100;
-
- /*
- * If not much of the ram is mapped, makes the imbalance
- * less relevant, it's high priority we refill the inactive
- * list with mapped pages only in presence of high ratio of
- * mapped pages.
- *
- * Max temporary value is vm_total_pages*100.
- */
- imbalance *= mapped_ratio;
- imbalance /= 100;
-
- /* apply imbalance feedback to swap_tendency */
- swap_tendency += imbalance;
-
- /*
- * Now use this metric to decide whether to start moving mapped
- * memory onto the inactive list.
- */
- if (swap_tendency >= 100)
- reclaim_mapped = 1;
-
- return reclaim_mapped;
+ return zone->pages_scanned >= (zone_lru_pages(zone) * 3);
}
/*
static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
- struct scan_control *sc, int priority)
+ struct scan_control *sc, int priority, int file)
{
unsigned long pgmoved;
int pgdeactivate = 0;
LIST_HEAD(l_inactive);
struct page *page;
struct pagevec pvec;
- int reclaim_mapped = 0;
-
- if (sc->may_swap)
- reclaim_mapped = calc_reclaim_mapped(sc, zone, priority);
+ enum lru_list lru;
lru_add_drain();
spin_lock_irq(&zone->lru_lock);
pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
ISOLATE_ACTIVE, zone,
- sc->mem_cgroup, 1);
+ sc->mem_cgroup, 1, file);
/*
* zone->pages_scanned is used for detect zone's oom
* mem_cgroup remembers nr_scan by itself.
*/
- if (scan_global_lru(sc))
+ if (scan_global_lru(sc)) {
zone->pages_scanned += pgscanned;
+ zone->recent_scanned[!!file] += pgmoved;
+ }
- __mod_zone_page_state(zone, NR_ACTIVE, -pgmoved);
+ if (file)
+ __mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
+ else
+ __mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved);
spin_unlock_irq(&zone->lru_lock);
while (!list_empty(&l_hold)) {
cond_resched();
page = lru_to_page(&l_hold);
list_del(&page->lru);
- if (page_mapped(page)) {
- if (!reclaim_mapped ||
- (total_swap_pages == 0 && PageAnon(page)) ||
- page_referenced(page, 0, sc->mem_cgroup)) {
- list_add(&page->lru, &l_active);
- continue;
- }
- }
list_add(&page->lru, &l_inactive);
}
+ /*
+ * Now put the pages back on the appropriate [file or anon] inactive
+ * and active lists.
+ */
pagevec_init(&pvec, 1);
pgmoved = 0;
+ lru = LRU_BASE + file * LRU_FILE;
spin_lock_irq(&zone->lru_lock);
while (!list_empty(&l_inactive)) {
page = lru_to_page(&l_inactive);
VM_BUG_ON(!PageActive(page));
ClearPageActive(page);
- list_move(&page->lru, &zone->lru[LRU_INACTIVE].list);
+ list_move(&page->lru, &zone->lru[lru].list);
mem_cgroup_move_lists(page, false);
pgmoved++;
if (!pagevec_add(&pvec, page)) {
- __mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
spin_unlock_irq(&zone->lru_lock);
pgdeactivate += pgmoved;
pgmoved = 0;
spin_lock_irq(&zone->lru_lock);
}
}
- __mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
pgdeactivate += pgmoved;
if (buffer_heads_over_limit) {
spin_unlock_irq(&zone->lru_lock);
}
pgmoved = 0;
+ lru = LRU_ACTIVE + file * LRU_FILE;
while (!list_empty(&l_active)) {
page = lru_to_page(&l_active);
prefetchw_prev_lru_page(page, &l_active, flags);
SetPageLRU(page);
VM_BUG_ON(!PageActive(page));
- list_move(&page->lru, &zone->lru[LRU_ACTIVE].list);
+ list_move(&page->lru, &zone->lru[lru].list);
mem_cgroup_move_lists(page, true);
pgmoved++;
if (!pagevec_add(&pvec, page)) {
- __mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
pgmoved = 0;
spin_unlock_irq(&zone->lru_lock);
if (vm_swap_full())
spin_lock_irq(&zone->lru_lock);
}
}
- __mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
+ zone->recent_rotated[!!file] += pgmoved;
__count_zone_vm_events(PGREFILL, zone, pgscanned);
__count_vm_events(PGDEACTIVATE, pgdeactivate);
pagevec_release(&pvec);
}
-static unsigned long shrink_list(enum lru_list l, unsigned long nr_to_scan,
+static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
struct zone *zone, struct scan_control *sc, int priority)
{
- if (l == LRU_ACTIVE) {
- shrink_active_list(nr_to_scan, zone, sc, priority);
+ int file = is_file_lru(lru);
+
+ if (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE) {
+ shrink_active_list(nr_to_scan, zone, sc, priority, file);
return 0;
}
- return shrink_inactive_list(nr_to_scan, zone, sc);
+ return shrink_inactive_list(nr_to_scan, zone, sc, file);
+}
+
+/*
+ * Determine how aggressively the anon and file LRU lists should be
+ * scanned. The relative value of each set of LRU lists is determined
+ * by looking at the fraction of the pages scanned we did rotate back
+ * onto the active list instead of evict.
+ *
+ * percent[0] specifies how much pressure to put on ram/swap backed
+ * memory, while percent[1] determines pressure on the file LRUs.
+ */
+static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
+ unsigned long *percent)
+{
+ unsigned long anon, file, free;
+ unsigned long anon_prio, file_prio;
+ unsigned long ap, fp;
+
+ anon = zone_page_state(zone, NR_ACTIVE_ANON) +
+ zone_page_state(zone, NR_INACTIVE_ANON);
+ file = zone_page_state(zone, NR_ACTIVE_FILE) +
+ zone_page_state(zone, NR_INACTIVE_FILE);
+ free = zone_page_state(zone, NR_FREE_PAGES);
+
+ /* If we have no swap space, do not bother scanning anon pages. */
+ if (nr_swap_pages <= 0) {
+ percent[0] = 0;
+ percent[1] = 100;
+ return;
+ }
+
+ /* If we have very few page cache pages, force-scan anon pages. */
+ if (unlikely(file + free <= zone->pages_high)) {
+ percent[0] = 100;
+ percent[1] = 0;
+ return;
+ }
+
+ /*
+ * OK, so we have swap space and a fair amount of page cache
+ * pages. We use the recently rotated / recently scanned
+ * ratios to determine how valuable each cache is.
+ *
+ * Because workloads change over time (and to avoid overflow)
+ * we keep these statistics as a floating average, which ends
+ * up weighing recent references more than old ones.
+ *
+ * anon in [0], file in [1]
+ */
+ if (unlikely(zone->recent_scanned[0] > anon / 4)) {
+ spin_lock_irq(&zone->lru_lock);
+ zone->recent_scanned[0] /= 2;
+ zone->recent_rotated[0] /= 2;
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
+ if (unlikely(zone->recent_scanned[1] > file / 4)) {
+ spin_lock_irq(&zone->lru_lock);
+ zone->recent_scanned[1] /= 2;
+ zone->recent_rotated[1] /= 2;
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
+ /*
+ * With swappiness at 100, anonymous and file have the same priority.
+ * This scanning priority is essentially the inverse of IO cost.
+ */
+ anon_prio = sc->swappiness;
+ file_prio = 200 - sc->swappiness;
+
+ /*
+ * anon recent_rotated[0]
+ * %anon = 100 * ----------- / ----------------- * IO cost
+ * anon + file rotate_sum
+ */
+ ap = (anon_prio + 1) * (zone->recent_scanned[0] + 1);
+ ap /= zone->recent_rotated[0] + 1;
+
+ fp = (file_prio + 1) * (zone->recent_scanned[1] + 1);
+ fp /= zone->recent_rotated[1] + 1;
+
+ /* Normalize to percentages */
+ percent[0] = 100 * ap / (ap + fp + 1);
+ percent[1] = 100 - percent[0];
}
+
/*
* This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
*/
unsigned long nr[NR_LRU_LISTS];
unsigned long nr_to_scan;
unsigned long nr_reclaimed = 0;
+ unsigned long percent[2]; /* anon @ 0; file @ 1 */
enum lru_list l;
- if (scan_global_lru(sc)) {
- /*
- * Add one to nr_to_scan just to make sure that the kernel
- * will slowly sift through the active list.
- */
- for_each_lru(l) {
- zone->lru[l].nr_scan += (zone_page_state(zone,
- NR_LRU_BASE + l) >> priority) + 1;
+ get_scan_ratio(zone, sc, percent);
+
+ for_each_lru(l) {
+ if (scan_global_lru(sc)) {
+ int file = is_file_lru(l);
+ int scan;
+ /*
+ * Add one to nr_to_scan just to make sure that the
+ * kernel will slowly sift through each list.
+ */
+ scan = zone_page_state(zone, NR_LRU_BASE + l);
+ if (priority) {
+ scan >>= priority;
+ scan = (scan * percent[file]) / 100;
+ }
+ zone->lru[l].nr_scan += scan + 1;
nr[l] = zone->lru[l].nr_scan;
if (nr[l] >= sc->swap_cluster_max)
zone->lru[l].nr_scan = 0;
else
nr[l] = 0;
+ } else {
+ /*
+ * This reclaim occurs not because zone memory shortage
+ * but because memory controller hits its limit.
+ * Don't modify zone reclaim related data.
+ */
+ nr[l] = mem_cgroup_calc_reclaim(sc->mem_cgroup, zone,
+ priority, l);
}
- } else {
- /*
- * This reclaim occurs not because zone memory shortage but
- * because memory controller hits its limit.
- * Then, don't modify zone reclaim related data.
- */
- nr[LRU_ACTIVE] = mem_cgroup_calc_reclaim(sc->mem_cgroup,
- zone, priority, LRU_ACTIVE);
-
- nr[LRU_INACTIVE] = mem_cgroup_calc_reclaim(sc->mem_cgroup,
- zone, priority, LRU_INACTIVE);
}
- while (nr[LRU_ACTIVE] || nr[LRU_INACTIVE]) {
+ while (nr[LRU_ACTIVE_ANON] || nr[LRU_INACTIVE_ANON] ||
+ nr[LRU_ACTIVE_FILE] || nr[LRU_INACTIVE_FILE]) {
for_each_lru(l) {
if (nr[l]) {
nr_to_scan = min(nr[l],
return nr_reclaimed;
}
-
+
/*
* This is the main entry point to direct page reclaim.
*
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_page_state(zone, NR_ACTIVE)
- + zone_page_state(zone, NR_INACTIVE);
+ lru_pages += zone_lru_pages(zone);
}
}
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
- lru_pages += zone_page_state(zone, NR_ACTIVE)
- + zone_page_state(zone, NR_INACTIVE);
+ lru_pages += zone_lru_pages(zone);
}
/*
if (zone_is_all_unreclaimable(zone))
continue;
if (nr_slab == 0 && zone->pages_scanned >=
- (zone_page_state(zone, NR_ACTIVE)
- + zone_page_state(zone, NR_INACTIVE)) * 6)
+ (zone_lru_pages(zone) * 6))
zone_set_flag(zone,
ZONE_ALL_UNRECLAIMABLE);
/*
/*
* The background pageout daemon, started as a kernel thread
- * from the init process.
+ * from the init process.
*
* This basically trickles out pages so that we have _some_
* free memory available even if there is no other activity
wake_up_interruptible(&pgdat->kswapd_wait);
}
+unsigned long global_lru_pages(void)
+{
+ 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);
+}
+
#ifdef CONFIG_PM
/*
* Helper function for shrink_all_memory(). Tries to reclaim 'nr_pages' pages
for_each_lru(l) {
/* For pass = 0 we don't shrink the active list */
- if (pass == 0 && l == LRU_ACTIVE)
+ if (pass == 0 &&
+ (l == LRU_ACTIVE || l == LRU_ACTIVE_FILE))
continue;
zone->lru[l].nr_scan +=
return ret;
}
-static unsigned long count_lru_pages(void)
-{
- return global_page_state(NR_ACTIVE) + global_page_state(NR_INACTIVE);
-}
-
/*
* Try to free `nr_pages' of memory, system-wide, and return the number of
* freed pages.
current->reclaim_state = &reclaim_state;
- lru_pages = count_lru_pages();
+ lru_pages = global_lru_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,
- count_lru_pages());
+ global_lru_pages());
ret += reclaim_state.reclaimed_slab;
if (ret >= nr_pages)
goto out;
if (!ret) {
do {
reclaim_state.reclaimed_slab = 0;
- shrink_slab(nr_pages, sc.gfp_mask, count_lru_pages());
+ shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
ret += reclaim_state.reclaimed_slab;
} while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff