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From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Michal Hocko <mhocko@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	xishi.qiuxishi@alibaba-inc.com,
	Laurent Dufour <ldufour@linux.vnet.ibm.com>
Subject: [RFC][PATCH v1 05/11] mm: hwpoison-inject: don't pin for hwpoison_filter()
Date: Fri,  9 Nov 2018 15:47:09 +0900	[thread overview]
Message-ID: <1541746035-13408-6-git-send-email-n-horiguchi@ah.jp.nec.com> (raw)
In-Reply-To: <1541746035-13408-1-git-send-email-n-horiguchi@ah.jp.nec.com>

Another memory error injection interface debugfs:hwpoison/corrupt-pfn
also takes bogus refcount for hwpoison_filter(). It's justified
because this does a coarse filter, expecting that memory_failure()
redoes the check for sure.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
 mm/hwpoison-inject.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git v4.19-mmotm-2018-10-30-16-08/mm/hwpoison-inject.c v4.19-mmotm-2018-10-30-16-08_patched/mm/hwpoison-inject.c
index b6ac706..766062c 100644
--- v4.19-mmotm-2018-10-30-16-08/mm/hwpoison-inject.c
+++ v4.19-mmotm-2018-10-30-16-08_patched/mm/hwpoison-inject.c
@@ -25,11 +25,6 @@ static int hwpoison_inject(void *data, u64 val)
 
 	p = pfn_to_page(pfn);
 	hpage = compound_head(p);
-	/*
-	 * This implies unable to support free buddy pages.
-	 */
-	if (!get_hwpoison_page(p))
-		return 0;
 
 	if (!hwpoison_filter_enable)
 		goto inject;
@@ -39,23 +34,20 @@ static int hwpoison_inject(void *data, u64 val)
 	 * This implies unable to support non-LRU pages.
 	 */
 	if (!PageLRU(hpage) && !PageHuge(p))
-		goto put_out;
+		return 0;
 
 	/*
-	 * do a racy check with elevated page count, to make sure PG_hwpoison
-	 * will only be set for the targeted owner (or on a free page).
+	 * do a racy check to make sure PG_hwpoison will only be set for
+	 * the targeted owner (or on a free page).
 	 * memory_failure() will redo the check reliably inside page lock.
 	 */
 	err = hwpoison_filter(hpage);
 	if (err)
-		goto put_out;
+		return 0;
 
 inject:
 	pr_info("Injecting memory failure at pfn %#lx\n", pfn);
-	return memory_failure(pfn, MF_COUNT_INCREASED);
-put_out:
-	put_hwpoison_page(p);
-	return 0;
+	return memory_failure(pfn, 0);
 }
 
 static int hwpoison_unpoison(void *data, u64 val)
-- 
2.7.0


  parent reply	other threads:[~2018-11-09  6:47 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-09  6:47 [PATCH RFC v1 00/11] hwpoison improvement part 1 Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 01/11] mm: hwpoison: cleanup unused PageHuge() check Naoya Horiguchi
2018-11-09  9:52   ` Anshuman Khandual
2018-11-09  6:47 ` [RFC][PATCH v1 02/11] mm: soft-offline: add missing error check of set_hwpoison_free_buddy_page() Naoya Horiguchi
2018-11-09 10:20   ` Anshuman Khandual
2018-11-13  0:16     ` Naoya Horiguchi
2018-11-14  8:53       ` Anshuman Khandual
2018-11-09  6:47 ` [RFC][PATCH v1 03/11] mm: move definition of num_poisoned_pages_inc/dec to include/linux/mm.h Naoya Horiguchi
2018-11-09 10:28   ` Anshuman Khandual
2018-11-13  0:17     ` Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 04/11] mm: madvise: call soft_offline_page() without MF_COUNT_INCREASED Naoya Horiguchi
2018-11-09 10:46   ` Anshuman Khandual
2018-11-13  0:18     ` Naoya Horiguchi
2018-11-09  6:47 ` Naoya Horiguchi [this message]
2018-11-09  6:47 ` [RFC][PATCH v1 06/11] mm: hwpoison: remove MF_COUNT_INCREASED Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 07/11] mm: remove flag argument from soft offline functions Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 08/11] mm: soft-offline: isolate error pages from buddy freelist Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 09/11] mm: hwpoison: apply buddy page handling code to hard-offline Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 10/11] mm: clear PageHWPoison in memory hotremove Naoya Horiguchi
2018-11-13  1:32   ` Naoya Horiguchi
2018-11-09  6:47 ` [RFC][PATCH v1 11/11] mm: hwpoison: introduce clear_hwpoison_free_buddy_page() Naoya Horiguchi
2018-11-09 11:33   ` Anshuman Khandual
2018-11-13  0:19     ` Naoya Horiguchi
2018-11-14  8:23       ` Anshuman Khandual

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