[PATCH 1/4] vmscan: simplify shrink_inactive_list()
From: KOSAKI Motohiro
Date: Thu Apr 15 2010 - 06:23:16 EST
Now, max_scan of shrink_inactive_list() is always passed less than
SWAP_CLUSTER_MAX. then, we can remove scanning pages loop in it.
This patch also help stack diet.
detail
- remove "while (nr_scanned < max_scan)" loop
- remove nr_freed (now, we use nr_reclaimed directly)
- remove nr_scan (now, we use nr_scanned directly)
- rename max_scan to nr_to_scan
- pass nr_to_scan into isolate_pages() directly instead
using SWAP_CLUSTER_MAX
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
mm/vmscan.c | 190 ++++++++++++++++++++++++++++-------------------------------
1 files changed, 89 insertions(+), 101 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index eab6028..4de4029 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1137,16 +1137,22 @@ static int too_many_isolated(struct zone *zone, int file,
* 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,
+static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
struct zone *zone, struct scan_control *sc,
int file)
{
LIST_HEAD(page_list);
struct pagevec pvec;
- unsigned long nr_scanned = 0;
+ unsigned long nr_scanned;
unsigned long nr_reclaimed = 0;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
int lumpy_reclaim = 0;
+ struct page *page;
+ unsigned long nr_taken;
+ unsigned long nr_active;
+ unsigned int count[NR_LRU_LISTS] = { 0, };
+ unsigned long nr_anon;
+ unsigned long nr_file;
while (unlikely(too_many_isolated(zone, file, sc))) {
congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1172,119 +1178,101 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
lru_add_drain();
spin_lock_irq(&zone->lru_lock);
- do {
- struct page *page;
- unsigned long nr_taken;
- unsigned long nr_scan;
- unsigned long nr_freed;
- 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(SWAP_CLUSTER_MAX,
- &page_list, &nr_scan, sc->order, mode,
- zone, sc->mem_cgroup, 0, file);
+ nr_taken = sc->isolate_pages(nr_to_scan,
+ &page_list, &nr_scanned, sc->order,
+ lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE,
+ 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 (scanning_global_lru(sc)) {
+ zone->pages_scanned += nr_scanned;
+ if (current_is_kswapd())
+ __count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scanned);
+ else
+ __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scanned);
+ }
- if (nr_taken == 0)
- goto done;
+ if (nr_taken == 0)
+ goto done;
- nr_active = clear_active_flags(&page_list, count);
- __count_vm_events(PGDEACTIVATE, nr_active);
+ nr_active = clear_active_flags(&page_list, count);
+ __count_vm_events(PGDEACTIVATE, nr_active);
- __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]);
+ __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]);
- 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);
+ 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] += nr_anon;
- reclaim_stat->recent_scanned[1] += nr_file;
+ reclaim_stat->recent_scanned[0] += nr_anon;
+ reclaim_stat->recent_scanned[1] += nr_file;
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irq(&zone->lru_lock);
- nr_scanned += nr_scan;
- nr_freed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC);
+ nr_reclaimed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC);
+
+ /*
+ * If we are direct reclaiming for contiguous pages and we do
+ * not reclaim everything in the list, try again and wait
+ * for IO to complete. This will stall high-order allocations
+ * but that should be acceptable to the caller
+ */
+ if (nr_reclaimed < nr_taken && !current_is_kswapd() && lumpy_reclaim) {
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
- * If we are direct reclaiming for contiguous pages and we do
- * not reclaim everything in the list, try again and wait
- * for IO to complete. This will stall high-order allocations
- * but that should be acceptable to the caller
+ * The attempt at page out may have made some
+ * of the pages active, mark them inactive again.
*/
- if (nr_freed < nr_taken && !current_is_kswapd() &&
- lumpy_reclaim) {
- congestion_wait(BLK_RW_ASYNC, HZ/10);
-
- /*
- * The attempt at page out may have made some
- * of the pages active, mark them inactive again.
- */
- nr_active = clear_active_flags(&page_list, count);
- count_vm_events(PGDEACTIVATE, nr_active);
-
- nr_freed += shrink_page_list(&page_list, sc,
- PAGEOUT_IO_SYNC);
- }
+ nr_active = clear_active_flags(&page_list, count);
+ count_vm_events(PGDEACTIVATE, nr_active);
- nr_reclaimed += nr_freed;
+ nr_reclaimed += shrink_page_list(&page_list, sc,
+ PAGEOUT_IO_SYNC);
+ }
- local_irq_disable();
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_STEAL, nr_freed);
- __count_zone_vm_events(PGSTEAL, zone, nr_freed);
+ local_irq_disable();
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_STEAL, nr_reclaimed);
+ __count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
- spin_lock(&zone->lru_lock);
- /*
- * Put back any unfreeable pages.
- */
- while (!list_empty(&page_list)) {
- int lru;
- page = lru_to_page(&page_list);
- VM_BUG_ON(PageLRU(page));
- list_del(&page->lru);
- if (unlikely(!page_evictable(page, NULL))) {
- spin_unlock_irq(&zone->lru_lock);
- putback_lru_page(page);
- spin_lock_irq(&zone->lru_lock);
- continue;
- }
- SetPageLRU(page);
- lru = page_lru(page);
- add_page_to_lru_list(zone, page, lru);
- if (is_active_lru(lru)) {
- int file = is_file_lru(lru);
- reclaim_stat->recent_rotated[file]++;
- }
- if (!pagevec_add(&pvec, page)) {
- spin_unlock_irq(&zone->lru_lock);
- __pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
- }
+ spin_lock(&zone->lru_lock);
+ /*
+ * Put back any unfreeable pages.
+ */
+ while (!list_empty(&page_list)) {
+ int lru;
+ page = lru_to_page(&page_list);
+ VM_BUG_ON(PageLRU(page));
+ list_del(&page->lru);
+ if (unlikely(!page_evictable(page, NULL))) {
+ spin_unlock_irq(&zone->lru_lock);
+ putback_lru_page(page);
+ spin_lock_irq(&zone->lru_lock);
+ continue;
}
- __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);
+ SetPageLRU(page);
+ lru = page_lru(page);
+ add_page_to_lru_list(zone, page, lru);
+ if (is_active_lru(lru)) {
+ int file = is_file_lru(lru);
+ reclaim_stat->recent_rotated[file]++;
+ }
+ if (!pagevec_add(&pvec, page)) {
+ spin_unlock_irq(&zone->lru_lock);
+ __pagevec_release(&pvec);
+ 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);
done:
spin_unlock_irq(&zone->lru_lock);
--
1.6.5.2
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