The patch titled
Subject: mm: fix negative nr_isolated counts
has been removed from the -mm tree. Its filename was
mm-fix-negative-nr_isolated-counts.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Hugh Dickins <hu...@google.com>
Subject: mm: fix negative nr_isolated counts
The vmstat interfaces are good at hiding negative counts (at least when
CONFIG_SMP); but if you peer behind the curtain, you find that
nr_isolated_anon and nr_isolated_file soon go negative, and grow ever more
negative: so they can absorb larger and larger numbers of isolated pages,
yet still appear to be zero.
I'm happy to avoid a congestion_wait() when too_many_isolated() myself;
but I guess it's there for a good reason, in which case we ought to get
too_many_isolated() working again.
The imbalance comes from isolate_migratepages()'s ISOLATE_ABORT case:
putback_movable_pages() decrements the NR_ISOLATED counts, but we forgot
to call acct_isolated() to increment them.
It is possible that the bug whcih this patch fixes could cause OOM kills
when the system still has a lot of reclaimable page cache.
Fixes: edc2ca612496 ("mm, compaction: move pageblock checks up from
isolate_migratepages_range()")
Signed-off-by: Hugh Dickins <hu...@google.com>
Acked-by: Vlastimil Babka <vba...@suse.cz>
Acked-by: Joonsoo Kim <iamjoonsoo....@lge.com>
Cc: <stable@vger.kernel.org> [3.18+]
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
---
mm/compaction.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN mm/compaction.c~mm-fix-negative-nr_isolated-counts mm/compaction.c
--- a/mm/compaction.c~mm-fix-negative-nr_isolated-counts
+++ a/mm/compaction.c
@@ -1103,8 +1103,10 @@ static isolate_migrate_t isolate_migrate
low_pfn = isolate_migratepages_block(cc, low_pfn, end_pfn,
isolate_mode);
- if (!low_pfn || cc->contended)
+ if (!low_pfn || cc->contended) {
+ acct_isolated(zone, cc);
return ISOLATE_ABORT;
+ }
/*
* Either we isolated something and proceed with migration. Or
_
Patches currently in -mm which might be from hu...@google.com are
origin.patch
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