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From: Oscar Salvador <osalvador@suse.de>
To: n-horiguchi@ah.jp.nec.com
Cc: mhocko@kernel.org, mike.kravetz@oracle.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Oscar Salvador <osalvador@suse.de>
Subject: [RFC PATCH v2 14/16] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline
Date: Thu, 17 Oct 2019 16:21:21 +0200
Message-ID: <20191017142123.24245-15-osalvador@suse.de> (raw)
In-Reply-To: <20191017142123.24245-1-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/:

        Whe 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 an 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>
---
 mm/madvise.c        | 3 ---
 mm/memory-failure.c | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 8a0b1f901d72..9ca48345ce45 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -887,9 +887,6 @@ 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 a/mm/memory-failure.c b/mm/memory-failure.c
index 3d491c0d3f91..c038896bedf0 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1767,7 +1767,7 @@ 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))
@@ -1866,7 +1866,7 @@ int soft_offline_page(struct page *page)
 
 	if (PageHWPoison(page)) {
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		return 0;
 	}
 
 	get_online_mems();
-- 
2.12.3



  parent reply index

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-17 14:21 [RFC PATCH v2 00/16] Hwpoison rework {hard,soft}-offline Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 01/16] mm,hwpoison: cleanup unused PageHuge() check Oscar Salvador
2019-10-18 11:48   ` Michal Hocko
2019-10-21  7:00     ` Naoya Horiguchi
2019-10-21 12:16       ` Michal Hocko
2019-11-12 12:22       ` Aneesh Kumar K.V
2019-11-13  6:02         ` Naoya Horiguchi
2019-10-17 14:21 ` [RFC PATCH v2 02/16] mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED Oscar Salvador
2019-10-18 11:52   ` Michal Hocko
2019-10-21  7:02     ` Naoya Horiguchi
2019-10-21 12:20       ` Michal Hocko
2019-10-17 14:21 ` [RFC PATCH v2 03/16] mm,madvise: Refactor madvise_inject_error Oscar Salvador
2019-10-21  7:03   ` Naoya Horiguchi
2019-10-17 14:21 ` [RFC PATCH v2 04/16] mm,hwpoison-inject: don't pin for hwpoison_filter Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 05/16] mm,hwpoison: Un-export get_hwpoison_page and make it static Oscar Salvador
2019-10-21  7:03   ` Naoya Horiguchi
2019-10-17 14:21 ` [RFC PATCH v2 06/16] mm,hwpoison: Kill put_hwpoison_page Oscar Salvador
2019-10-21  7:04   ` Naoya Horiguchi
2019-10-17 14:21 ` [RFC PATCH v2 07/16] mm,hwpoison: remove MF_COUNT_INCREASED Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 08/16] mm,hwpoison: remove flag argument from soft offline functions Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 09/16] mm,hwpoison: Unify THP handling for hard and soft offline Oscar Salvador
2019-10-21  7:04   ` Naoya Horiguchi
2019-10-21  9:51     ` [PATCH 17/16] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP Naoya Horiguchi
2019-10-22  8:00       ` Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 10/16] mm,hwpoison: Rework soft offline for free pages Oscar Salvador
2019-10-18 12:06   ` Michal Hocko
2019-10-21 12:58     ` Oscar Salvador
2019-10-21 15:41       ` Michal Hocko
2019-10-22  7:46         ` Oscar Salvador
2019-10-22  8:26           ` Michal Hocko
2019-10-22  8:35             ` Oscar Salvador
2019-10-22  9:22               ` Michal Hocko
2019-10-22  9:58                 ` Oscar Salvador
2019-10-22 10:24                   ` Michal Hocko
2019-10-22 10:33                     ` Oscar Salvador
2019-10-23  2:15                       ` Naoya Horiguchi
2019-10-23  2:01                   ` Naoya Horiguchi
2019-10-21  7:45   ` Naoya Horiguchi
2019-10-22  8:00     ` Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 11/16] mm,hwpoison: Rework soft offline for in-use pages Oscar Salvador
2019-10-18 12:39   ` Michal Hocko
2019-10-21 13:48     ` Oscar Salvador
2019-10-21 14:06       ` Michal Hocko
2019-10-22  7:56         ` Oscar Salvador
2019-10-22  8:30           ` Michal Hocko
2019-10-22  9:40             ` Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 12/16] mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 13/16] mm,hwpoison: Take pages off the buddy when hard-offlining Oscar Salvador
2019-10-17 14:21 ` Oscar Salvador [this message]
2019-10-21  9:20   ` [RFC PATCH v2 14/16] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline Naoya Horiguchi
2019-10-17 14:21 ` [RFC PATCH v2 15/16] mm/hwpoison-inject: Rip off duplicated checks Oscar Salvador
2019-10-21  9:40   ` David Hildenbrand
2019-10-22  7:57     ` Oscar Salvador
2019-10-17 14:21 ` [RFC PATCH v2 16/16] mm, soft-offline: convert parameter to pfn Oscar Salvador
2019-10-18  8:15   ` David Hildenbrand
2020-06-11 16:43 ` [RFC PATCH v2 00/16] Hwpoison rework {hard,soft}-offline Dmitry Yakunin
2020-06-15  6:19   ` HORIGUCHI NAOYA(堀口 直也)

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