lkml.org 
[lkml]   [2012]   [Feb]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH v2 18/22] mm: handle lruvec relocks in compaction
From
Date
Prepare for lru_lock splitting in memory compaction code.

* disable irqs in acct_isolated() for __mod_zone_page_state(),
lru_lock isn't required there.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
---
mm/compaction.c | 30 ++++++++++++++++--------------
1 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index a976b28..1e89165 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -224,8 +224,10 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc)
list_for_each_entry(page, &cc->migratepages, lru)
count[!!page_is_file_cache(page)]++;

+ local_irq_disable();
__mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
__mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+ local_irq_enable();
}

/* Similar to reclaim, but different enough that they don't share logic */
@@ -262,7 +264,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
unsigned long nr_scanned = 0, nr_isolated = 0;
struct list_head *migratelist = &cc->migratepages;
isolate_mode_t mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE;
- struct lruvec *lruvec;
+ struct lruvec *lruvec = NULL;

/* Do not scan outside zone boundaries */
low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);
@@ -294,25 +296,24 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,

/* Time to isolate some pages for migration */
cond_resched();
- spin_lock_irq(&zone->lru_lock);
for (; low_pfn < end_pfn; low_pfn++) {
struct page *page;
- bool locked = true;

/* give a chance to irqs before checking need_resched() */
if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) {
- spin_unlock_irq(&zone->lru_lock);
- locked = false;
+ if (lruvec)
+ unlock_lruvec_irq(lruvec);
+ lruvec = NULL;
}
- if (need_resched() || spin_is_contended(&zone->lru_lock)) {
- if (locked)
- spin_unlock_irq(&zone->lru_lock);
+ if (need_resched() ||
+ (lruvec && spin_is_contended(&zone->lru_lock))) {
+ if (lruvec)
+ unlock_lruvec_irq(lruvec);
+ lruvec = NULL;
cond_resched();
- spin_lock_irq(&zone->lru_lock);
if (fatal_signal_pending(current))
break;
- } else if (!locked)
- spin_lock_irq(&zone->lru_lock);
+ }

/*
* migrate_pfn does not necessarily start aligned to a
@@ -359,7 +360,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
continue;
}

- if (!PageLRU(page))
+ if (!catch_page_lruvec(&lruvec, page))
continue;

/*
@@ -382,7 +383,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
VM_BUG_ON(PageTransCompound(page));

/* Successfully isolated */
- lruvec = page_lruvec(page);
del_page_from_lru_list(lruvec, page, page_lru(page));
list_add(&page->lru, migratelist);
cc->nr_migratepages++;
@@ -395,9 +395,11 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
}
}

+ if (lruvec)
+ unlock_lruvec_irq(lruvec);
+
acct_isolated(zone, cc);

- spin_unlock_irq(&zone->lru_lock);
cc->migrate_pfn = low_pfn;

trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);


\
 
 \ /
  Last update: 2012-02-20 18:37    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site