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From:   Huang Ying <ying.huang@intel.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Huang Ying <ying.huang@intel.com>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Oscar Salvador <osalvador@suse.de>, Zi Yan <ziy@nvidia.com>,
        Yang Shi <shy828301@gmail.com>
Subject: [PATCH -V3 4/8] migrate_pages(): fix failure counting for THP subpages retrying
Date:   Wed, 17 Aug 2022 16:14:04 +0800
Message-Id: <20220817081408.513338-5-ying.huang@intel.com>
In-Reply-To: <20220817081408.513338-1-ying.huang@intel.com>
References: <20220817081408.513338-1-ying.huang@intel.com>
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If THP is failed to be migrated for -ENOSYS and -ENOMEM, the THP will
be split into thp_split_pages, and after other pages are migrated,
pages in thp_split_pages will be migrated with no_subpage_counting ==
true, because its failure have been counted already.  If some pages in
thp_split_pages are retried during migration, we should not count
their failure if no_subpage_counting == true too.  This is done this
patch to fix the failure counting for THP subpages retrying.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
---
 mm/migrate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index ae55f08e72ce..0018b5191799 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1545,7 +1545,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 			}
 		}
 	}
-	nr_failed += retry;
+	if (!no_subpage_counting)
+		nr_failed += retry;
 	nr_thp_failed += thp_retry;
 	/*
 	 * Try to migrate subpages of fail-to-migrate THPs, no nr_failed
-- 
2.30.2