[PATCH v2 09/10] compaction: make compaction use in-order putback

From: Minchan Kim
Date: Sun May 29 2011 - 14:15:04 EST


Compaction is good solution to get contiguous page but it makes
LRU churing which is not good.
This patch makes that compaction code use in-order putback so
after compaction completion, migrated pages are keeping LRU ordering.

Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx>
---
mm/compaction.c | 26 ++++++++++++++------------
1 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index e218562..00e710a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -28,7 +28,7 @@
*/
struct compact_control {
struct list_head freepages; /* List of free pages to migrate to */
- struct list_head migratepages; /* List of pages being migrated */
+ struct inorder_lru migratepages;/* List of pages being migrated */
unsigned long nr_freepages; /* Number of isolated free pages */
unsigned long nr_migratepages; /* Number of pages to migrate */
unsigned long free_pfn; /* isolate_freepages search base */
@@ -210,7 +210,7 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc)
struct page *page;
unsigned int count[2] = { 0, };

- list_for_each_entry(page, &cc->migratepages, lru)
+ list_for_each_migrate_entry(page, &cc->migratepages, ilru)
count[!!page_is_file_cache(page)]++;

__mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
@@ -242,7 +242,7 @@ static unsigned long isolate_migratepages(struct zone *zone,
unsigned long low_pfn, end_pfn;
unsigned long last_pageblock_nr = 0, pageblock_nr;
unsigned long nr_scanned = 0, nr_isolated = 0;
- struct list_head *migratelist = &cc->migratepages;
+ struct inorder_lru *migratelist = &cc->migratepages;
enum ISOLATE_PAGE_MODE mode = ISOLATE_BOTH;

/* Do not scan outside zone boundaries */
@@ -273,7 +273,7 @@ static unsigned long isolate_migratepages(struct zone *zone,
cond_resched();
spin_lock_irq(&zone->lru_lock);
for (; low_pfn < end_pfn; low_pfn++) {
- struct page *page;
+ struct page *page, *prev_page;
bool locked = true;

/* give a chance to irqs before checking need_resched() */
@@ -330,14 +330,15 @@ static unsigned long isolate_migratepages(struct zone *zone,
/* Try isolate the page */
if (!cc->sync)
mode |= ISOLATE_CLEAN;
- if (__isolate_lru_page(page, mode, 0) != 0)
+ if (__isolate_inorder_lru_page(page, mode, 0, &prev_page) != 0)
continue;

VM_BUG_ON(PageTransCompound(page));

/* Successfully isolated */
del_page_from_lru_list(zone, page, page_lru(page));
- list_add(&page->lru, migratelist);
+ migratelist_add(page, prev_page, migratelist);
+
cc->nr_migratepages++;
nr_isolated++;

@@ -393,7 +394,7 @@ static void update_nr_listpages(struct compact_control *cc)
int nr_freepages = 0;
struct page *page;

- list_for_each_entry(page, &cc->migratepages, lru)
+ list_for_each_migrate_entry(page, &cc->migratepages, ilru)
nr_migratepages++;
list_for_each_entry(page, &cc->freepages, lru)
nr_freepages++;
@@ -521,7 +522,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
continue;

nr_migrate = cc->nr_migratepages;
- err = migrate_pages(&cc->migratepages, compaction_alloc,
+ err = migrate_inorder_lru_pages(&cc->migratepages,
+ compaction_alloc,
(unsigned long)cc, false,
cc->sync);
update_nr_listpages(cc);
@@ -536,7 +538,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)

/* Release LRU pages not migrated */
if (err) {
- putback_lru_pages(&cc->migratepages);
+ putback_inorder_lru_pages(&cc->migratepages);
cc->nr_migratepages = 0;
}

@@ -562,7 +564,7 @@ unsigned long compact_zone_order(struct zone *zone,
.sync = sync,
};
INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
+ INIT_MIGRATE_LIST(&cc.migratepages);

return compact_zone(zone, &cc);
}
@@ -644,12 +646,12 @@ static int compact_node(int nid)

cc.zone = zone;
INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
+ INIT_MIGRATE_LIST(&cc.migratepages);

compact_zone(zone, &cc);

VM_BUG_ON(!list_empty(&cc.freepages));
- VM_BUG_ON(!list_empty(&cc.migratepages));
+ VM_BUG_ON(!migratelist_empty(&cc.migratepages));
}

return 0;
--
1.7.0.4

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