From: Naoya Horiguchi <nao.horiguchi@gmail.com>
To: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@suse.com>, Ding Hui <dinghui@sangfor.com.cn>,
Tony Luck <tony.luck@intel.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Naoya Horiguchi <naoya.horiguchi@nec.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v1 2/6] mm/hwpoison: remove race consideration
Date: Mon, 14 Jun 2021 11:12:08 +0900 [thread overview]
Message-ID: <20210614021212.223326-3-nao.horiguchi@gmail.com> (raw)
In-Reply-To: <20210614021212.223326-1-nao.horiguchi@gmail.com>
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Now memory_failure() and unpoison_memory() are protected by mf_mutex,
so no need to explicitly check races between them. So remove them.
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
---
mm/memory-failure.c | 37 -------------------------------------
1 file changed, 37 deletions(-)
diff --git v5.13-rc5/mm/memory-failure.c v5.13-rc5_patched/mm/memory-failure.c
index 280eb6d6dd15..e7910386fc9c 100644
--- v5.13-rc5/mm/memory-failure.c
+++ v5.13-rc5_patched/mm/memory-failure.c
@@ -1461,14 +1461,6 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
lock_page(head);
page_flags = head->flags;
- if (!PageHWPoison(head)) {
- pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
- num_poisoned_pages_dec();
- unlock_page(head);
- put_page(head);
- return 0;
- }
-
/*
* TODO: hwpoison for pud-sized hugetlb doesn't work right now, so
* simply disable it. In order to make it work properly, we need
@@ -1730,16 +1722,6 @@ int memory_failure(unsigned long pfn, int flags)
*/
page_flags = p->flags;
- /*
- * unpoison always clear PG_hwpoison inside page lock
- */
- if (!PageHWPoison(p)) {
- pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
- num_poisoned_pages_dec();
- unlock_page(p);
- put_page(p);
- goto unlock_mutex;
- }
if (hwpoison_filter(p)) {
if (TestClearPageHWPoison(p))
num_poisoned_pages_dec();
@@ -1956,17 +1938,6 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}
- /*
- * unpoison_memory() can encounter thp only when the thp is being
- * worked by memory_failure() and the page lock is not held yet.
- * In such case, we yield to memory_failure() and make unpoison fail.
- */
- if (!PageHuge(page) && PageTransHuge(page)) {
- unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n",
- pfn, &unpoison_rs);
- goto unlock_mutex;
- }
-
if (!get_hwpoison_page(p, flags)) {
if (TestClearPageHWPoison(p))
num_poisoned_pages_dec();
@@ -1975,20 +1946,12 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}
- lock_page(page);
- /*
- * This test is racy because PG_hwpoison is set outside of page lock.
- * That's acceptable because that won't trigger kernel panic. Instead,
- * the PG_hwpoison page will be caught and isolated on the entrance to
- * the free buddy page pool.
- */
if (TestClearPageHWPoison(page)) {
unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
pfn, &unpoison_rs);
num_poisoned_pages_dec();
freeit = 1;
}
- unlock_page(page);
put_page(page);
if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
--
2.25.1
next prev parent reply other threads:[~2021-06-14 2:13 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-14 2:12 [PATCH v1 0/6] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-06-14 2:12 ` [PATCH v1 1/6] mm/hwpoison: mf_mutex for soft offline and unpoison Naoya Horiguchi
2021-06-15 11:41 ` Ding Hui
2021-06-15 11:55 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-15 12:42 ` Miaohe Lin
2021-06-16 0:41 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-16 3:14 ` Miaohe Lin
2021-06-14 2:12 ` Naoya Horiguchi [this message]
2021-06-15 12:57 ` [PATCH v1 2/6] mm/hwpoison: remove race consideration Ding Hui
2021-06-16 0:11 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-16 0:40 ` Ding Hui
2021-06-14 2:12 ` [PATCH v1 3/6] mm/hwpoison: introduce MF_MSG_PAGETABLE Naoya Horiguchi
2021-06-14 3:06 ` Matthew Wilcox
2021-06-14 3:55 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-14 2:12 ` [PATCH v1 4/6] mm/hwpoison: remove MF_MSG_BUDDY_2ND and MF_MSG_POISONED_HUGE Naoya Horiguchi
2021-06-14 2:12 ` [PATCH v1 5/6] mm/hwpoison: make some kernel pages handlable Naoya Horiguchi
2021-07-28 10:59 ` Ding Hui
2021-07-29 6:54 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-14 2:12 ` [PATCH v1 6/6] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-06-17 10:00 ` Ding Hui
2021-06-18 8:36 ` HORIGUCHI NAOYA(堀口 直也)
2021-06-19 12:22 ` Ding Hui
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