aboutsummaryrefslogtreecommitdiff
path: root/mm/compaction.c
diff options
context:
space:
mode:
authorShaohua Li <shli@kernel.org>2012-10-08 16:32:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 16:22:48 +0900
commite64c5237cf6ff474cb2f3f832f48f2b441dd9979 (patch)
tree88fb8ec8e9e2d32051aaacf90a306f7b124e4135 /mm/compaction.c
parentf2d52fe51c8c0a18cf5fbe583bad51090d12c146 (diff)
downloadlinux-e64c5237cf6ff474cb2f3f832f48f2b441dd9979.tar.gz
mm: compaction: abort compaction loop if lock is contended or run too long
isolate_migratepages_range() might isolate no pages if for example when zone->lru_lock is contended and running asynchronous compaction. In this case, we should abort compaction, otherwise, compact_zone will run a useless loop and make zone->lru_lock is even contended. An additional check is added to ensure that cc.migratepages and cc.freepages get properly drained whan compaction is aborted. [minchan@kernel.org: Putback pages isolated for migration if aborting] [akpm@linux-foundation.org: compact_zone_order requires non-NULL arg contended] [akpm@linux-foundation.org: make compact_zone_order() require non-NULL arg `contended'] [minchan@kernel.org: Putback pages isolated for migration if aborting] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 1f61bcbd626..0649cc1b347 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -70,8 +70,7 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags,
/* async aborts if taking too long or contended */
if (!cc->sync) {
- if (cc->contended)
- *cc->contended = true;
+ cc->contended = true;
return false;
}
@@ -688,7 +687,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
/* Perform the isolation */
low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn);
- if (!low_pfn)
+ if (!low_pfn || cc->contended)
return ISOLATE_ABORT;
cc->migrate_pfn = low_pfn;
@@ -848,6 +847,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
switch (isolate_migratepages(zone, cc)) {
case ISOLATE_ABORT:
ret = COMPACT_PARTIAL;
+ putback_lru_pages(&cc->migratepages);
+ cc->nr_migratepages = 0;
goto out;
case ISOLATE_NONE:
continue;
@@ -896,6 +897,7 @@ static unsigned long compact_zone_order(struct zone *zone,
bool sync, bool *contended,
struct page **page)
{
+ unsigned long ret;
struct compact_control cc = {
.nr_freepages = 0,
.nr_migratepages = 0,
@@ -903,13 +905,18 @@ static unsigned long compact_zone_order(struct zone *zone,
.migratetype = allocflags_to_migratetype(gfp_mask),
.zone = zone,
.sync = sync,
- .contended = contended,
.page = page,
};
INIT_LIST_HEAD(&cc.freepages);
INIT_LIST_HEAD(&cc.migratepages);
- return compact_zone(zone, &cc);
+ ret = compact_zone(zone, &cc);
+
+ VM_BUG_ON(!list_empty(&cc.freepages));
+ VM_BUG_ON(!list_empty(&cc.migratepages));
+
+ *contended = cc.contended;
+ return ret;
}
int sysctl_extfrag_threshold = 500;