From 7b49514fa1dbe05813f099179ebe3d982f45e87e Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu, 19 May 2022 20:50:28 +0800
Subject: [PATCH] mm/madvise: free hwpoison and swapin error entry in
madvise_free_pte_range
Once the MADV_FREE operation has succeeded, callers can expect they might
get zero-fill pages if accessing the memory again. Therefore it should be
safe to delete the hwpoison entry and swapin error entry. There is no
reason to kill the process if it has called MADV_FREE on the range.
Link: https://lkml.kernel.org/r/20220519125030.21486-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/madvise.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/mm/madvise.c b/mm/madvise.c
index 4d6592488b516..5f45375115328 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -624,11 +624,14 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
swp_entry_t entry;
entry = pte_to_swp_entry(ptent);
- if (non_swap_entry(entry))
- continue;
- nr_swap--;
- free_swap_and_cache(entry);
- pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
+ if (!non_swap_entry(entry)) {
+ nr_swap--;
+ free_swap_and_cache(entry);
+ pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
+ } else if (is_hwpoison_entry(entry) ||
+ is_swapin_error_entry(entry)) {
+ pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
+ }
continue;
}
--
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