From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Lance Yang <lance.yang@linux.dev>, Nico Pache <npache@redhat.com>,
akpm@linux-foundation.org, david@kernel.org, ziy@nvidia.com,
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hughd@google.com, richard.weiyang@gmail.com,
David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org
Subject: Re: [PATCH mm-unstable v14 03/16] introduce collapse_single_pmd to unify khugepaged and madvise_collapse
Date: Mon, 26 Jan 2026 12:25:41 +0000 [thread overview]
Message-ID: <7e666361-24cd-4eb4-a591-73a8900bdb5c@lucifer.local> (raw)
In-Reply-To: <b1747380-1f2e-4edd-81fe-f01b3fd01bad@linux.alibaba.com>
On Fri, Jan 23, 2026 at 05:31:17PM +0800, Baolin Wang wrote:
>
>
> On 1/23/26 1:07 PM, Lance Yang wrote:
> >
> >
> > After collapse_single_pmd() returns, mmap_lock might have been released.
> > Between
> > that unlock and here, another thread could unmap/remap the VMA, making
> > the vma
> > pointer stale when we access vma->vm_file?
> >
> > Would it be safer to get the file reference before calling
> > collapse_single_pmd()?
> > Or we need to revalidate the VMA after getting the lock back?
> Good catch. I think we can move the filemap_write_and_wait_range() related
> logic into collapse_single_pmd(), after we get a file reference.
Good suggestion, is what Nico did in the suggested patch :) Agreed better there.
Thanks, Lorenzo
next prev parent reply other threads:[~2026-01-26 12:25 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-22 19:28 [PATCH mm-unstable v14 00/16] khugepaged: mTHP support Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 01/16] mm: introduce is_pmd_order helper Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 02/16] khugepaged: rename hpage_collapse_* to collapse_* Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 03/16] introduce collapse_single_pmd to unify khugepaged and madvise_collapse Nico Pache
2026-01-23 5:07 ` Lance Yang
2026-01-23 9:31 ` Baolin Wang
2026-01-26 12:25 ` Lorenzo Stoakes [this message]
2026-01-23 23:26 ` Nico Pache
2026-01-24 4:41 ` Lance Yang
2026-01-26 12:25 ` Lorenzo Stoakes
2026-01-26 11:40 ` Lorenzo Stoakes
2026-01-26 15:09 ` Andrew Morton
2026-01-26 15:18 ` Lorenzo Stoakes
2026-01-28 16:38 ` Nico Pache
2026-02-03 11:43 ` Lorenzo Stoakes
2026-02-03 11:35 ` Lorenzo Stoakes
2026-01-22 19:28 ` [PATCH mm-unstable v14 04/16] khugepaged: generalize hugepage_vma_revalidate for mTHP support Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 05/16] khugepaged: generalize alloc_charge_folio() Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 06/16] khugepaged: generalize __collapse_huge_page_* for mTHP support Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 07/16] khugepaged: introduce collapse_max_ptes_none helper function Nico Pache
2026-02-03 12:08 ` Lorenzo Stoakes
2026-02-04 21:39 ` Nico Pache
2026-02-06 17:44 ` Nico Pache
2026-02-16 15:16 ` Lorenzo Stoakes
2026-01-22 19:28 ` [PATCH mm-unstable v14 08/16] khugepaged: generalize collapse_huge_page for mTHP collapse Nico Pache
2026-02-03 13:07 ` Lorenzo Stoakes
2026-02-04 22:00 ` Nico Pache
2026-02-16 15:20 ` Lorenzo Stoakes
2026-01-22 19:28 ` [PATCH mm-unstable v14 09/16] khugepaged: skip collapsing mTHP to smaller orders Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 10/16] khugepaged: add per-order mTHP collapse failure statistics Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 11/16] khugepaged: improve tracepoints for mTHP orders Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 12/16] khugepaged: introduce collapse_allowable_orders helper function Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 13/16] khugepaged: Introduce mTHP collapse support Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 14/16] khugepaged: avoid unnecessary mTHP collapse attempts Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 15/16] khugepaged: run khugepaged for all orders Nico Pache
2026-01-22 19:28 ` [PATCH mm-unstable v14 16/16] Documentation: mm: update the admin guide for mTHP collapse Nico Pache
2026-01-26 11:21 ` [PATCH mm-unstable v14 00/16] khugepaged: mTHP support Lorenzo Stoakes
2026-01-26 11:32 ` Lorenzo Stoakes
2026-02-04 21:35 ` Nico Pache
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