The patch titled
Subject: mm: compaction: abort compaction loop if lock is contended or run too long
has been removed from the -mm tree. Its filename was
mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Shaohua Li <shli@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx: Putback pages isolated for migration if aborting]
[akpm@xxxxxxxxxxxxxxxxxxxx: compact_zone_order requires non-NULL arg contended]
[akpm@xxxxxxxxxxxxxxxxxxxx: make compact_zone_order() require non-NULL arg `contended']
[minchan@xxxxxxxxxx: Putback pages isolated for migration if aborting]
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 17 ++++++++++++-----
mm/internal.h | 2 +-
2 files changed, 13 insertions(+), 6 deletions(-)
diff -puN mm/compaction.c~mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long mm/compaction.c
--- a/mm/compaction.c~mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long
+++ a/mm/compaction.c
@@ -70,8 +70,7 @@ static bool compact_checklock_irqsave(sp
/* 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_migrate
/* 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 *zon
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(
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(
.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;
diff -puN mm/internal.h~mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long mm/internal.h
--- a/mm/internal.h~mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long
+++ a/mm/internal.h
@@ -130,7 +130,7 @@ struct compact_control {
int order; /* order a direct compactor needs */
int migratetype; /* MOVABLE, RECLAIMABLE etc */
struct zone *zone;
- bool *contended; /* True if a lock was contended */
+ bool contended; /* True if a lock was contended */
struct page **page; /* Page captured of requested size */
};
_
Patches currently in -mm which might be from shli@xxxxxxxxxx are
origin.patch
linux-next.patch
swap-add-a-simple-detector-for-inappropriate-swapin-readahead.patch
swap-add-a-simple-detector-for-inappropriate-swapin-readahead-fix.patch
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