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From:   Miaohe Lin <linmiaohe@huawei.com>
To:     <akpm@linux-foundation.org>
CC:     <naoya.horiguchi@nec.com>, <mhocko@suse.com>, <minchan@kernel.org>,
        <cgoldswo@codeaurora.org>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <linmiaohe@huawei.com>
Subject: [PATCH 2/3] mm/memory_hotplug: fix potential permanent lru cache disable
Date:   Sat, 21 Aug 2021 17:42:45 +0800
Message-ID: <20210821094246.10149-3-linmiaohe@huawei.com>
In-Reply-To: <20210821094246.10149-1-linmiaohe@huawei.com>
References: <20210821094246.10149-1-linmiaohe@huawei.com>
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If offline_pages failed after lru_cache_disable(), it forgot to do
lru_cache_enable() in error path. So we would have lru cache disabled
permanently in this case.

Fixes: d479960e44f2 ("mm: disable LRU pagevec during the migration temporarily")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 mm/memory_hotplug.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d986d3791986..9fd0be32a281 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -2033,6 +2033,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 	undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
 	memory_notify(MEM_CANCEL_OFFLINE, &arg);
 failed_removal_pcplists_disabled:
+	lru_cache_enable();
 	zone_pcp_enable(zone);
 failed_removal:
 	pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n",
-- 
2.23.0