From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>
Cc: <ziy@nvidia.com>, <william.kucharski@oracle.com>,
<willy@infradead.org>, <yang.shi@linux.alibaba.com>,
<aneesh.kumar@linux.ibm.com>, <rcampbell@nvidia.com>,
<songliubraving@fb.com>, <kirill.shutemov@linux.intel.com>,
<riel@surriel.com>, <hannes@cmpxchg.org>, <minchan@kernel.org>,
<hughd@google.com>, <adobriyan@gmail.com>,
<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<linux-fsdevel@vger.kernel.org>, <linmiaohe@huawei.com>
Subject: [PATCH v3 5/5] mm/huge_memory.c: don't discard hugepage if other processes are mapping it
Date: Tue, 11 May 2021 21:48:57 +0800 [thread overview]
Message-ID: <20210511134857.1581273-6-linmiaohe@huawei.com> (raw)
In-Reply-To: <20210511134857.1581273-1-linmiaohe@huawei.com>
If other processes are mapping any other subpages of the hugepage, i.e. in
pte-mapped thp case, page_mapcount() will return 1 incorrectly. Then we
would discard the page while other processes are still mapping it. Fix it
by using total_mapcount() which can tell whether other processes are still
mapping it.
Fixes: b8d3c4c3009d ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called")
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/huge_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b8e67332806f..24647fe076b8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1610,7 +1610,7 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
* If other processes are mapping this page, we couldn't discard
* the page unless they all do MADV_FREE so let's skip the page.
*/
- if (page_mapcount(page) != 1)
+ if (total_mapcount(page) != 1)
goto out;
if (!trylock_page(page))
--
2.23.0
prev parent reply other threads:[~2021-05-11 13:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 13:48 [PATCH v3 0/5] Cleanup and fixup for huge_memory Miaohe Lin
2021-05-11 13:48 ` [PATCH v3 1/5] mm/huge_memory.c: remove dedicated macro HPAGE_CACHE_INDEX_MASK Miaohe Lin
2021-05-11 13:48 ` [PATCH v3 2/5] mm/huge_memory.c: use page->deferred_list Miaohe Lin
2021-05-11 23:03 ` Matthew Wilcox
2021-05-12 2:02 ` Miaohe Lin
2021-05-11 13:48 ` [PATCH v3 3/5] mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled() Miaohe Lin
2021-05-13 21:30 ` Yang Shi
2021-05-14 1:53 ` Miaohe Lin
2021-05-11 13:48 ` [PATCH v3 4/5] mm/huge_memory.c: remove unnecessary tlb_remove_page_size() for huge zero pmd Miaohe Lin
2021-05-11 13:48 ` Miaohe Lin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210511134857.1581273-6-linmiaohe@huawei.com \
--to=linmiaohe@huawei.com \
--cc=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=rcampbell@nvidia.com \
--cc=riel@surriel.com \
--cc=songliubraving@fb.com \
--cc=william.kucharski@oracle.com \
--cc=willy@infradead.org \
--cc=yang.shi@linux.alibaba.com \
--cc=ziy@nvidia.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).