From: Miaohe Lin <linmiaohe@huawei.com>
Date: Wed, 25 Aug 2021 19:17:55 +0000 (-0700)
Subject: mm/memory_hotplug: fix potential permanent lru cache disable
X-Git-Tag: v5.13.14~96
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dbce1780abeb4236a94378bca2ba9f60700280d8;p=thirdparty%2Fkernel%2Fstable.git

mm/memory_hotplug: fix potential permanent lru cache disable

commit 946746d1ad921e5f493b536533dda02ea22ca609 upstream.

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.

Link: https://lkml.kernel.org/r/20210821094246.10149-3-linmiaohe@huawei.com
Fixes: d479960e44f2 ("mm: disable LRU pagevec during the migration temporarily")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 70620d0dd923a..1bf3f86812509 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1854,6 +1854,7 @@ failed_removal_isolated:
 	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",