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From: nao.horiguchi@gmail.com
To: linux-mm@kvack.org
Cc: mhocko@kernel.org, akpm@linux-foundation.org,
	mike.kravetz@oracle.com, osalvador@suse.de, tony.luck@intel.com,
	david@redhat.com, aneesh.kumar@linux.vnet.ibm.com,
	zeil@yandex-team.ru, naoya.horiguchi@nec.com,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 14/15] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline
Date: Wed, 24 Jun 2020 15:01:36 +0000
Message-ID: <20200624150137.7052-15-nao.horiguchi@gmail.com> (raw)
In-Reply-To: <20200624150137.7052-1-nao.horiguchi@gmail.com>

From: Oscar Salvador <osalvador@suse.de>

Currently, there is an inconsistency when calling soft-offline from
different paths on a page that is already poisoned.

1) madvise:

        madvise_inject_error skips any poisoned page and continues
        the loop.
        If that was the only page to madvise, it returns 0.

2) /sys/devices/system/memory/:

        When calling soft_offline_page_store()->soft_offline_page(),
        we return -EBUSY in case the page is already poisoned.
        This is inconsistent with a) the above example and b)
        memory_failure, where we return 0 if the page was poisoned.

Fix this by dropping the PageHWPoison() check in madvise_inject_error,
and let soft_offline_page return 0 if it finds the page already poisoned.

Please, note that this represents a user-api change, since now the
return error when calling soft_offline_page_store()->soft_offline_page()
will be different.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
---
 mm/madvise.c        | 3 ---
 mm/memory-failure.c | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git v5.8-rc1-mmots-2020-06-20-21-44/mm/madvise.c v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/madvise.c
index 2b5080253406..b59bbd6c9982 100644
--- v5.8-rc1-mmots-2020-06-20-21-44/mm/madvise.c
+++ v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/madvise.c
@@ -902,9 +902,6 @@ static int madvise_inject_error(int behavior,
 		 */
 		put_page(page);
 
-		if (PageHWPoison(page))
-			continue;
-
 		if (behavior == MADV_SOFT_OFFLINE) {
 			pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
 				pfn, start);
diff --git v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c
index 22c904f6d17a..9ad3198a3954 100644
--- v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c
+++ v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c
@@ -1800,7 +1800,7 @@ static int __soft_offline_page(struct page *page)
 		unlock_page(page);
 		put_page(page);
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		return 0;
 	}
 
 	if (!PageHuge(page))
@@ -1901,7 +1901,7 @@ int soft_offline_page(unsigned long pfn)
 
 	if (PageHWPoison(page)) {
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		return 0;
 	}
 
 	get_online_mems();
-- 
2.17.1



  parent reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-24 15:01 [PATCH v3 00/15] HWPOISON: soft offline rework nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 01/15] mm,hwpoison: cleanup unused PageHuge() check nao.horiguchi
2020-06-30 23:28   ` Mike Kravetz
2020-06-24 15:01 ` [PATCH v3 02/15] mm, hwpoison: remove recalculating hpage nao.horiguchi
2020-06-30 23:45   ` Mike Kravetz
2020-06-24 15:01 ` [PATCH v3 03/15] mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 04/15] mm,madvise: Refactor madvise_inject_error nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 05/15] mm,hwpoison-inject: don't pin for hwpoison_filter nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 06/15] mm,hwpoison: Un-export get_hwpoison_page and make it static nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 07/15] mm,hwpoison: Kill put_hwpoison_page nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 08/15] mm,hwpoison: remove MF_COUNT_INCREASED nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 09/15] mm,hwpoison: remove flag argument from soft offline functions nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 10/15] mm,hwpoison: Unify THP handling for hard and soft offline nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 11/15] mm,hwpoison: Rework soft offline for free pages nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 12/15] mm,hwpoison: Rework soft offline for in-use pages nao.horiguchi
2020-06-24 15:01 ` [PATCH v3 13/15] mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page nao.horiguchi
2020-06-26 16:53   ` Naresh Kamboju
2020-06-28  6:54     ` Naoya Horiguchi
2020-06-29  7:22       ` Stephen Rothwell
2020-06-29  7:33         ` HORIGUCHI NAOYA(堀口 直也)
2020-06-24 15:01 ` nao.horiguchi [this message]
2020-06-24 15:01 ` [PATCH v3 15/15] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP nao.horiguchi
2020-06-24 19:17 ` [PATCH v3 00/15] HWPOISON: soft offline rework Andrew Morton
2020-06-24 22:36   ` HORIGUCHI NAOYA(堀口 直也)
2020-06-24 22:49     ` Andrew Morton
2020-06-24 23:01       ` HORIGUCHI NAOYA(堀口 直也)
2020-06-26 13:35 ` Qian Cai
2020-06-29 10:29 ` Oscar Salvador
2020-06-30  6:50   ` HORIGUCHI NAOYA(堀口 直也)
2020-06-30  5:08 ` Qian Cai
2020-06-30  6:35   ` Oscar Salvador
2020-07-01  8:22     ` Oscar Salvador
2020-07-01  9:07       ` HORIGUCHI NAOYA(堀口 直也)
2020-07-14 10:08   ` Oscar Salvador

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