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 -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html