[PATCH 38/39] mm: use-once: use the generic shrinker logic

Peter Zijlstra
2006-07-12T14:44:27Z

Makes the use-once policy use the generic shrinker.
Based on ideas from Wu Fengguang.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

include/linux/mm_use_once_data.h | 2
include/linux/mm_use_once_policy.h | 5 -
mm/useonce.c | 156 +++++++++----------------------------
3 files changed, 45 insertions(+), 118 deletions(-)

Index: linux-2.6/mm/useonce.c
===================================================================
--- linux-2.6.orig/mm/useonce.c 2006-07-12 16:10:56.000000000 +0200
+++ linux-2.6/mm/useonce.c 2006-07-12 16:11:07.000000000 +0200
@@ -16,7 +16,7 @@ void __init pgrep_init_zone(struct zone
INIT_LIST_HEAD(&zone->policy.active_list);
INIT_LIST_HEAD(&zone->policy.inactive_list);
zone->policy.nr_scan_active = 0;
- zone->policy.nr_scan_inactive = 0;
+ zone->policy.nr_scan = 0;
zone->policy.nr_active = 0;
zone->policy.nr_inactive = 0;
}
@@ -78,73 +78,6 @@ void pgrep_reinsert(struct list_head *pa
}
}
/*
- * shrink_inactive_list() is a helper for shrink_zone(). It returns the number
- * of reclaimed pages
- */
-static unsigned long shrink_inactive_list(unsigned long max_scan,
- struct zone *zone, struct scan_control *sc)
-{
- LIST_HEAD(page_list);
- struct pagevec pvec;
- unsigned long nr_scanned = 0;
- unsigned long nr_reclaimed = 0;
- pagevec_init(&pvec, 1);
-
- pgrep_add_drain();
- spin_lock_irq(&zone->lru_lock);
- do {
- struct page *page;
- unsigned long nr_taken;
- unsigned long nr_scan;
- unsigned long nr_freed;
-
- nr_taken = isolate_lru_pages(zone, sc->swap_cluster_max,
- &zone->policy.inactive_list,
- &page_list, &nr_scan);
- spin_unlock_irq(&zone->lru_lock);
-
- nr_scanned += nr_scan;
- nr_freed = shrink_page_list(&page_list, sc);
- nr_reclaimed += nr_freed;
- local_irq_disable();
- if (current_is_kswapd()) {
- __mod_page_state_zone(zone, pgscan_kswapd, nr_scan);
- __mod_page_state(kswapd_steal, nr_freed);
- } else
- __mod_page_state_zone(zone, pgscan_direct, nr_scan);
- __mod_page_state_zone(zone, pgsteal, nr_freed);
-
- if (nr_taken == 0)
- goto done;
-
- spin_lock(&zone->lru_lock);
- /*
- * Put back any unfreeable pages.
- */
- while (!list_empty(&page_list)) {
- page = lru_to_page(&page_list);
- BUG_ON(PageLRU(page));
- SetPageLRU(page);
- list_del(&page->lru);
- if (PageActive(page))
- add_page_to_active_list(zone, page);
- else
- add_page_to_inactive_list(zone, page);
- if (!pagevec_add(&pvec, page)) {
- spin_unlock_irq(&zone->lru_lock);
- __pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
- }
- }
- } while (nr_scanned < max_scan);
- spin_unlock(&zone->lru_lock);
-done:
- local_irq_enable();
- pagevec_release(&pvec);
- return nr_reclaimed;
-}
-
-/*
* This moves pages from the active list to the inactive list.
*
* We move them the other way if the page is referenced by one or more
@@ -162,7 +95,7 @@ done:
* But we had to alter page->flags anyway.
*/
static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
- struct scan_control *sc, int reclaim_mapped)
+ int reclaim_mapped)
{
unsigned long pgmoved;
int pgdeactivate = 0;
@@ -174,9 +107,6 @@ static void shrink_active_list(unsigned
struct pagevec pvec;
int referenced;

- if (!sc->may_swap)
- reclaim_mapped = 0;
-
pgrep_add_drain();
spin_lock_irq(&zone->lru_lock);
pgmoved = isolate_lru_pages(zone, nr_pages, &zone->policy.active_list,
@@ -257,59 +187,53 @@ static void shrink_active_list(unsigned
pagevec_release(&pvec);
}

-/*
- * This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
- */
-unsigned long pgrep_shrink_zone(int priority, struct zone *zone,
- struct scan_control *sc)
+void __pgrep_get_candidates(struct zone *zone, int priority,
+ unsigned long nr_to_scan, struct list_head *pages,
+ unsigned long *nr_scanned)
{
- unsigned long nr_active;
- unsigned long nr_inactive;
- unsigned long nr_to_scan;
- unsigned long nr_reclaimed = 0;
- int reclaim_mapped = should_reclaim_mapped(zone);
+ unsigned long nr_taken;
+ unsigned long long nr_scan_active;

- atomic_inc(&zone->reclaim_in_progress);
+ nr_taken = isolate_lru_pages(zone, nr_to_scan,
+ &zone->policy.inactive_list, pages, nr_scanned);

- /*
- * Add one to `nr_to_scan' just to make sure that the kernel will
- * slowly sift through the active list.
- */
- zone->policy.nr_scan_active += (zone->policy.nr_active >> priority) + 1;
- nr_active = zone->policy.nr_scan_active;
- if (nr_active >= sc->swap_cluster_max)
- zone->policy.nr_scan_active = 0;
- else
- nr_active = 0;
+ nr_scan_active = nr_to_scan * zone->policy.nr_active * 1024ULL;
+ do_div(nr_scan_active, zone->policy.nr_inactive + nr_taken + 1UL);
+ zone->policy.nr_scan_active += nr_scan_active;
+}

- zone->policy.nr_scan_inactive += (zone->policy.nr_inactive >> priority) + 1;
- nr_inactive = zone->policy.nr_scan_inactive;
- if (nr_inactive >= sc->swap_cluster_max)
- zone->policy.nr_scan_inactive = 0;
- else
- nr_inactive = 0;
+void pgrep_put_candidates(struct zone *zone, struct list_head *pages,
+ unsigned long nr_freed, int may_swap)
+{
+ int reclaim_mapped = should_reclaim_mapped(zone);
+ struct pagevec pvec;

- while (nr_active || nr_inactive) {
- if (nr_active) {
- nr_to_scan = min(nr_active,
- (unsigned long)sc->swap_cluster_max);
- nr_active -= nr_to_scan;
- shrink_active_list(nr_to_scan, zone, sc, reclaim_mapped);
- }
+ pagevec_init(&pvec, 1);

- if (nr_inactive) {
- nr_to_scan = min(nr_inactive,
- (unsigned long)sc->swap_cluster_max);
- nr_inactive -= nr_to_scan;
- nr_reclaimed += shrink_inactive_list(nr_to_scan, zone,
- sc);
+ spin_lock_irq(&zone->lru_lock);
+ while (!list_empty(pages)) {
+ struct page *page = lru_to_page(pages);
+ BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+ list_del(&page->lru);
+ if (PageActive(page))
+ add_page_to_active_list(zone, page);
+ else
+ add_page_to_inactive_list(zone, page);
+ if (!pagevec_add(&pvec, page)) {
+ spin_unlock_irq(&zone->lru_lock);
+ __pagevec_release(&pvec);
+ spin_lock_irq(&zone->lru_lock);
}
}
+ spin_unlock_irq(&zone->lru_lock);

- throttle_vm_writeout();
+ pagevec_release(&pvec);

- atomic_dec(&zone->reclaim_in_progress);
- return nr_reclaimed;
+ while (zone->policy.nr_scan_active >= SWAP_CLUSTER_MAX * 1024UL) {
+ zone->policy.nr_scan_active -= SWAP_CLUSTER_MAX * 1024UL;
+ shrink_active_list(SWAP_CLUSTER_MAX, zone, reclaim_mapped);
+ }
}

#define K(x) ((x) << (PAGE_SHIFT-10))
@@ -359,7 +283,7 @@ void pgrep_zoneinfo(struct zone *zone, s
zone->policy.nr_active,
zone->policy.nr_inactive,
zone->pages_scanned,
- zone->policy.nr_scan_active, zone->policy.nr_scan_inactive,
+ zone->policy.nr_scan_active / 1024, zone->policy.nr_scan,
zone->spanned_pages,
zone->present_pages);
}
Index: linux-2.6/include/linux/mm_use_once_policy.h
===================================================================
--- linux-2.6.orig/include/linux/mm_use_once_policy.h 2006-07-12 16:10:56.000000000 +0200
+++ linux-2.6/include/linux/mm_use_once_policy.h 2006-07-12 16:10:56.000000000 +0200
@@ -147,7 +147,10 @@ static inline unsigned long __pgrep_nr_p
return zone->policy.nr_active + zone->policy.nr_inactive;
}

-#define MM_POLICY_HAS_SHRINKER
+static inline unsigned long __pgrep_nr_scan(struct zone *zone)
+{
+ return zone->policy.nr_inactive;
+}

#endif /* __KERNEL__ */
#endif /* _LINUX_MM_USEONCE_POLICY_H */
Index: linux-2.6/include/linux/mm_use_once_data.h
===================================================================
--- linux-2.6.orig/include/linux/mm_use_once_data.h 2006-07-12 16:09:19.000000000 +0200
+++ linux-2.6/include/linux/mm_use_once_data.h 2006-07-12 16:10:56.000000000 +0200
@@ -7,7 +7,7 @@ struct pgrep_data {
struct list_head active_list;
struct list_head inactive_list;
unsigned long nr_scan_active;
- unsigned long nr_scan_inactive;
+ unsigned long nr_scan;
unsigned long nr_active;
unsigned long nr_inactive;
};