From: Lance Yang <lance.yang@linux.dev>
To: baolin.wang@linux.alibaba.com
Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org,
hughd@google.com, willy@infradead.org, ziy@nvidia.com,
liam@infradead.org, npache@redhat.com, ryan.roberts@arm.com,
dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2 04/11] mm: khugepaged: add shmem mTHP collapse support
Date: Wed, 10 Jun 2026 20:13:31 +0800 [thread overview]
Message-ID: <20260610121331.83926-1-lance.yang@linux.dev> (raw)
In-Reply-To: <3895c09794739bbfae99d9e021ffacf8a51fb8e2.1781083630.git.baolin.wang@linux.alibaba.com>
On Wed, Jun 10, 2026 at 06:29:12PM +0800, Baolin Wang wrote:
[...]
>@@ -2808,7 +2875,7 @@ static enum scan_result collapse_single_pmd(unsigned long addr,
> mmap_read_unlock(mm);
> *lock_dropped = true;
> retry:
>- result = collapse_scan_file(mm, addr, file, pgoff, cc);
>+ result = collapse_scan_file(mm, vma, addr, file, pgoff, cc);
Looks unsafe to pass "vma" down here, since we have already dropped
mmap_read_unlock(mm) ...
A racing munmap() could leave it stale before collapse_scan_file() use
it, no?
Cheers, Lance
next prev parent reply other threads:[~2026-06-10 12:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-10 10:29 [RFC PATCH v2 00/11] add shmem mTHP collapse support Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 01/11] mm: khugepaged: add max_ptes_none check in collapse_file() Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 02/11] mm: khugepaged: generalize collapse_file() for shmem mTHP support Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 03/11] mm: khugepaged: add an order check for PMD-sized THP statistics Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 04/11] mm: khugepaged: add shmem mTHP collapse support Baolin Wang
2026-06-10 12:13 ` Lance Yang [this message]
2026-06-10 12:44 ` Lance Yang
2026-06-10 10:29 ` [RFC PATCH v2 05/11] mm: shmem: run khugepaged for all shmem mTHP orders Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 06/11] mm: khugepaged: allow khugepaged to check all shmem mTHP-sized orders Baolin Wang
2026-06-10 11:33 ` Lance Yang
2026-06-10 10:29 ` [RFC PATCH v2 07/11] mm: khugepaged: skip large folios that don't need to be collapsed Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 08/11] selftests: mm: extend the check_huge() to support mTHP check Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 09/11] selftests: mm: move gather_after_split_folio_orders() into vm_util.c file Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 10/11] selftests: mm: implement the mTHP-sized hugepage check helpers Baolin Wang
2026-06-10 10:29 ` [RFC PATCH v2 11/11] selftests: mm: add mTHP collapse test cases Baolin Wang
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