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authorRei Yamamoto <yamamoto.rei@jp.fujitsu.com>2022-05-13 16:48:57 -0700
committerAndrew Morton <akpm@linux-foundation.org>2022-05-13 16:48:57 -0700
commitbbe832b9db2e1ad21522f8f0bf02775fff8a0e0e (patch)
treec119e9205c64f6a6f6c188f98e58ee78138a3da2 /mm/compaction.c
parentd4a157f5a26fbf1f1fd5da47a4772a738306348f (diff)
downloadlwn-bbe832b9db2e1ad21522f8f0bf02775fff8a0e0e.tar.gz
lwn-bbe832b9db2e1ad21522f8f0bf02775fff8a0e0e.zip
mm, compaction: fast_find_migrateblock() should return pfn in the target zone
At present, pages not in the target zone are added to cc->migratepages list in isolate_migratepages_block(). As a result, pages may migrate between nodes unintentionally. This would be a serious problem for older kernels without commit a984226f457f849e ("mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec"), because it can corrupt the lru list by handling pages in list without holding proper lru_lock. Avoid returning a pfn outside the target zone in the case that it is not aligned with a pageblock boundary. Otherwise isolate_migratepages_block() will handle pages not in the target zone. Link: https://lkml.kernel.org/r/20220511044300.4069-1-yamamoto.rei@jp.fujitsu.com Fixes: 70b44595eafe ("mm, compaction: use free lists to quickly locate a migration source") Signed-off-by: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Don Dutile <ddutile@redhat.com> Cc: Wonhyuk Yang <vvghjk1234@gmail.com> Cc: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 0e0ef9e44530..1f89b969c12b 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1848,6 +1848,8 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
update_fast_start_pfn(cc, free_pfn);
pfn = pageblock_start_pfn(free_pfn);
+ if (pfn < cc->zone->zone_start_pfn)
+ pfn = cc->zone->zone_start_pfn;
cc->fast_search_fail = 0;
found_block = true;
set_pageblock_skip(freepage);