From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>, <naoya.horiguchi@nec.com>
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<linmiaohe@huawei.com>
Subject: [PATCH v2 4/8] mm/memory-failure.c: fix race with changing page more robustly
Date: Wed, 16 Feb 2022 17:14:27 +0800 [thread overview]
Message-ID: <20220216091431.39406-5-linmiaohe@huawei.com> (raw)
In-Reply-To: <20220216091431.39406-1-linmiaohe@huawei.com>
We're only intended to deal with the non-Compound page after we split thp
in memory_failure. However, the page could have changed compound pages due
to race window. If this happens, we could try again to hopefully handle the
page next round. Also remove unneeded orig_head. It's always equal to the
hpage. So we can use hpage directly and remove this redundant one.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/memory-failure.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 7e205d91b2d7..d66f642888be 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1690,7 +1690,6 @@ int memory_failure(unsigned long pfn, int flags)
{
struct page *p;
struct page *hpage;
- struct page *orig_head;
struct dev_pagemap *pgmap;
int res = 0;
unsigned long page_flags;
@@ -1736,7 +1735,7 @@ int memory_failure(unsigned long pfn, int flags)
goto unlock_mutex;
}
- orig_head = hpage = compound_head(p);
+ hpage = compound_head(p);
num_poisoned_pages_inc();
/*
@@ -1817,13 +1816,18 @@ int memory_failure(unsigned long pfn, int flags)
lock_page(p);
/*
- * The page could have changed compound pages during the locking.
- * If this happens just bail out.
+ * We're only intended to deal with the non-Compound page here.
+ * However, the page could have changed compound pages due to
+ * race window. If this happens, we could try again to hopefully
+ * handle the page next round.
*/
- if (PageCompound(p) && compound_head(p) != orig_head) {
- action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
- res = -EBUSY;
- goto unlock_page;
+ if (PageCompound(p)) {
+ if (TestClearPageHWPoison(p))
+ num_poisoned_pages_dec();
+ unlock_page(p);
+ put_page(p);
+ flags &= ~MF_COUNT_INCREASED;
+ goto try_again;
}
/*
--
2.23.0
next prev parent reply other threads:[~2022-02-16 9:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-16 9:14 [PATCH v2 0/8] A few cleanup and fixup patches for memory failure Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 1/8] mm/memory-failure.c: minor clean up for memory_failure_dev_pagemap Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 2/8] mm/memory-failure.c: catch unexpected -EFAULT from vma_address() Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 3/8] mm/memory-failure.c: rework the signaling logic in kill_proc Miaohe Lin
2022-02-16 9:14 ` Miaohe Lin [this message]
2022-02-18 1:13 ` [PATCH v2 4/8] mm/memory-failure.c: fix race with changing page more robustly HORIGUCHI NAOYA(堀口 直也)
2022-02-18 1:53 ` Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 5/8] mm/memory-failure.c: remove PageSlab check in hwpoison_filter_dev Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 6/8] mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings() Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 7/8] mm/memory-failure.c: remove obsolete comment in __soft_offline_page Miaohe Lin
2022-02-16 9:14 ` [PATCH v2 8/8] mm/memory-failure.c: remove unnecessary PageTransTail check Miaohe Lin
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