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-rw-r--r--mm/compaction.c142
1 files changed, 23 insertions, 119 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 4ac338af5120..7ea259d82a99 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -236,7 +236,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
*/
while (unlikely(too_many_isolated(zone))) {
/* async migration should just abort */
- if (cc->mode != COMPACT_SYNC)
+ if (!cc->sync)
return 0;
congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -304,8 +304,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
* satisfies the allocation
*/
pageblock_nr = low_pfn >> pageblock_order;
- if (cc->mode != COMPACT_SYNC &&
- last_pageblock_nr != pageblock_nr &&
+ if (!cc->sync && last_pageblock_nr != pageblock_nr &&
!migrate_async_suitable(get_pageblock_migratetype(page))) {
low_pfn += pageblock_nr_pages;
low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1;
@@ -326,7 +325,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
continue;
}
- if (cc->mode != COMPACT_SYNC)
+ if (!cc->sync)
mode |= ISOLATE_ASYNC_MIGRATE;
lruvec = mem_cgroup_page_lruvec(page, zone);
@@ -361,90 +360,27 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
#endif /* CONFIG_COMPACTION || CONFIG_CMA */
#ifdef CONFIG_COMPACTION
-/*
- * Returns true if MIGRATE_UNMOVABLE pageblock was successfully
- * converted to MIGRATE_MOVABLE type, false otherwise.
- */
-static bool rescue_unmovable_pageblock(struct page *page)
-{
- unsigned long pfn, start_pfn, end_pfn;
- struct page *start_page, *end_page;
-
- pfn = page_to_pfn(page);
- start_pfn = pfn & ~(pageblock_nr_pages - 1);
- end_pfn = start_pfn + pageblock_nr_pages;
-
- start_page = pfn_to_page(start_pfn);
- end_page = pfn_to_page(end_pfn);
-
- /* Do not deal with pageblocks that overlap zones */
- if (page_zone(start_page) != page_zone(end_page))
- return false;
-
- for (page = start_page, pfn = start_pfn; page < end_page; pfn++,
- page++) {
- if (!pfn_valid_within(pfn))
- continue;
-
- if (PageBuddy(page)) {
- int order = page_order(page);
-
- pfn += (1 << order) - 1;
- page += (1 << order) - 1;
-
- continue;
- } else if (page_count(page) == 0 || PageLRU(page))
- continue;
-
- return false;
- }
-
- set_pageblock_migratetype(page, MIGRATE_MOVABLE);
- move_freepages_block(page_zone(page), page, MIGRATE_MOVABLE);
- return true;
-}
-enum smt_result {
- GOOD_AS_MIGRATION_TARGET,
- FAIL_UNMOVABLE_TARGET,
- FAIL_BAD_TARGET,
-};
-
-/*
- * Returns GOOD_AS_MIGRATION_TARGET if the page is within a block
- * suitable for migration to, FAIL_UNMOVABLE_TARGET if the page
- * is within a MIGRATE_UNMOVABLE block, FAIL_BAD_TARGET otherwise.
- */
-static enum smt_result suitable_migration_target(struct page *page,
- struct compact_control *cc)
+/* Returns true if the page is within a block suitable for migration to */
+static bool suitable_migration_target(struct page *page)
{
int migratetype = get_pageblock_migratetype(page);
/* Don't interfere with memory hot-remove or the min_free_kbytes blocks */
if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
- return FAIL_BAD_TARGET;
+ return false;
/* If the page is a large free page, then allow migration */
if (PageBuddy(page) && page_order(page) >= pageblock_order)
- return GOOD_AS_MIGRATION_TARGET;
+ return true;
/* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
- if (cc->mode != COMPACT_ASYNC_UNMOVABLE &&
- migrate_async_suitable(migratetype))
- return GOOD_AS_MIGRATION_TARGET;
-
- if (cc->mode == COMPACT_ASYNC_MOVABLE &&
- migratetype == MIGRATE_UNMOVABLE)
- return FAIL_UNMOVABLE_TARGET;
-
- if (cc->mode != COMPACT_ASYNC_MOVABLE &&
- migratetype == MIGRATE_UNMOVABLE &&
- rescue_unmovable_pageblock(page))
- return GOOD_AS_MIGRATION_TARGET;
+ if (migrate_async_suitable(migratetype))
+ return true;
/* Otherwise skip the block */
- return FAIL_BAD_TARGET;
+ return false;
}
/*
@@ -478,13 +414,6 @@ static void isolate_freepages(struct zone *zone,
zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
/*
- * isolate_freepages() may be called more than once during
- * compact_zone_order() run and we want only the most recent
- * count.
- */
- cc->nr_pageblocks_skipped = 0;
-
- /*
* Isolate free pages until enough are available to migrate the
* pages on cc->migratepages. We stop searching if the migrate
* and free page scanners meet or enough free pages are isolated.
@@ -492,7 +421,6 @@ static void isolate_freepages(struct zone *zone,
for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages;
pfn -= pageblock_nr_pages) {
unsigned long isolated;
- enum smt_result ret;
if (!pfn_valid(pfn))
continue;
@@ -509,12 +437,9 @@ static void isolate_freepages(struct zone *zone,
continue;
/* Check the block is suitable for migration */
- ret = suitable_migration_target(page, cc);
- if (ret != GOOD_AS_MIGRATION_TARGET) {
- if (ret == FAIL_UNMOVABLE_TARGET)
- cc->nr_pageblocks_skipped++;
+ if (!suitable_migration_target(page))
continue;
- }
+
/*
* Found a block suitable for isolating free pages from. Now
* we disabled interrupts, double check things are ok and
@@ -523,14 +448,12 @@ static void isolate_freepages(struct zone *zone,
*/
isolated = 0;
spin_lock_irqsave(&zone->lock, flags);
- ret = suitable_migration_target(page, cc);
- if (ret == GOOD_AS_MIGRATION_TARGET) {
+ if (suitable_migration_target(page)) {
end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn);
isolated = isolate_freepages_block(pfn, end_pfn,
freelist, false);
nr_freepages += isolated;
- } else if (ret == FAIL_UNMOVABLE_TARGET)
- cc->nr_pageblocks_skipped++;
+ }
spin_unlock_irqrestore(&zone->lock, flags);
/*
@@ -762,9 +685,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
nr_migrate = cc->nr_migratepages;
err = migrate_pages(&cc->migratepages, compaction_alloc,
- (unsigned long)&cc->freepages, false,
- (cc->mode == COMPACT_SYNC) ? MIGRATE_SYNC_LIGHT
- : MIGRATE_ASYNC);
+ (unsigned long)cc, false,
+ cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC);
update_nr_listpages(cc);
nr_remaining = cc->nr_migratepages;
@@ -793,8 +715,7 @@ out:
static unsigned long compact_zone_order(struct zone *zone,
int order, gfp_t gfp_mask,
- enum compact_mode mode,
- unsigned long *nr_pageblocks_skipped)
+ bool sync)
{
struct compact_control cc = {
.nr_freepages = 0,
@@ -802,17 +723,12 @@ static unsigned long compact_zone_order(struct zone *zone,
.order = order,
.migratetype = allocflags_to_migratetype(gfp_mask),
.zone = zone,
- .mode = mode,
+ .sync = sync,
};
- unsigned long rc;
-
INIT_LIST_HEAD(&cc.freepages);
INIT_LIST_HEAD(&cc.migratepages);
- rc = compact_zone(zone, &cc);
- *nr_pageblocks_skipped = cc.nr_pageblocks_skipped;
-
- return rc;
+ return compact_zone(zone, &cc);
}
int sysctl_extfrag_threshold = 500;
@@ -837,8 +753,6 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
struct zoneref *z;
struct zone *zone;
int rc = COMPACT_SKIPPED;
- unsigned long nr_pageblocks_skipped;
- enum compact_mode mode;
/*
* Check whether it is worth even starting compaction. The order check is
@@ -855,22 +769,12 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
nodemask) {
int status;
- mode = sync ? COMPACT_SYNC : COMPACT_ASYNC_MOVABLE;
-retry:
- status = compact_zone_order(zone, order, gfp_mask, mode,
- &nr_pageblocks_skipped);
+ status = compact_zone_order(zone, order, gfp_mask, sync);
rc = max(status, rc);
/* If a normal allocation would succeed, stop compacting */
if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0))
break;
-
- if (rc == COMPACT_COMPLETE && mode == COMPACT_ASYNC_MOVABLE) {
- if (nr_pageblocks_skipped) {
- mode = COMPACT_ASYNC_UNMOVABLE;
- goto retry;
- }
- }
}
return rc;
@@ -904,7 +808,7 @@ static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
if (ok && cc->order > zone->compact_order_failed)
zone->compact_order_failed = cc->order + 1;
/* Currently async compaction is never deferred. */
- else if (!ok && cc->mode == COMPACT_SYNC)
+ else if (!ok && cc->sync)
defer_compaction(zone, cc->order);
}
@@ -919,7 +823,7 @@ int compact_pgdat(pg_data_t *pgdat, int order)
{
struct compact_control cc = {
.order = order,
- .mode = COMPACT_ASYNC_MOVABLE,
+ .sync = false,
};
return __compact_pgdat(pgdat, &cc);
@@ -929,7 +833,7 @@ static int compact_node(int nid)
{
struct compact_control cc = {
.order = -1,
- .mode = COMPACT_SYNC,
+ .sync = true,
};
return __compact_pgdat(NODE_DATA(nid), &cc);