[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20220216091431.39406-7-linmiaohe@huawei.com>
Date: Wed, 16 Feb 2022 17:14:29 +0800
From: Miaohe Lin <linmiaohe@...wei.com>
To: <akpm@...ux-foundation.org>, <naoya.horiguchi@....com>
CC: <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
<linmiaohe@...wei.com>
Subject: [PATCH v2 6/8] mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings()
Only for hugetlb pages in shared mappings, try_to_unmap should take
semaphore in write mode here. Rework the code to make it clear.
Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@....com>
---
mm/memory-failure.c | 34 +++++++++++++++-------------------
1 file changed, 15 insertions(+), 19 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 791d89e0c15a..0100d4f9da9a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1404,26 +1404,22 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (kill)
collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
- if (!PageHuge(hpage)) {
- try_to_unmap(hpage, ttu);
+ if (PageHuge(hpage) && !PageAnon(hpage)) {
+ /*
+ * For hugetlb pages in shared mappings, try_to_unmap
+ * could potentially call huge_pmd_unshare. Because of
+ * this, take semaphore in write mode here and set
+ * TTU_RMAP_LOCKED to indicate we have taken the lock
+ * at this higher level.
+ */
+ mapping = hugetlb_page_mapping_lock_write(hpage);
+ if (mapping) {
+ try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
+ } else
+ pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
} else {
- if (!PageAnon(hpage)) {
- /*
- * For hugetlb pages in shared mappings, try_to_unmap
- * could potentially call huge_pmd_unshare. Because of
- * this, take semaphore in write mode here and set
- * TTU_RMAP_LOCKED to indicate we have taken the lock
- * at this higher level.
- */
- mapping = hugetlb_page_mapping_lock_write(hpage);
- if (mapping) {
- try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
- i_mmap_unlock_write(mapping);
- } else
- pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
- } else {
- try_to_unmap(hpage, ttu);
- }
+ try_to_unmap(hpage, ttu);
}
unmap_success = !page_mapped(hpage);
--
2.23.0
Powered by blists - more mailing lists