From: "Oscar Salvador (SUSE)" <osalvador@kernel.org>
To: Wupeng Ma <mawupeng1@huawei.com>
Cc: muchun.song@linux.dev, osalvador@suse.de, david@kernel.org,
akpm@linux-foundation.org, ljs@kernel.org,
Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org,
surenb@google.com, mhocko@suse.com, linmiaohe@huawei.com,
nao.horiguchi@gmail.com, mike.kravetz@oracle.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] mm/memory-failure: fix hugetlb_lock AA deadlock in get_huge_page_for_hwpoison
Date: Wed, 20 May 2026 10:13:42 +0200 [thread overview]
Message-ID: <ag1tNtzmjNlrj4Xm@localhost.localdomain> (raw)
In-Reply-To: <20260520020128.3506168-1-mawupeng1@huawei.com>
On Wed, May 20, 2026 at 10:01:28AM +0800, Wupeng Ma wrote:
> madvise(MADV_HWPOISON) can trigger a recursive spinlock self-deadlock
> (AA deadlock) on hugetlb_lock due to a race with concurrent folio
> unmapping. The race scenario:
>
> Thread 1 (madvise MADV_HWPOISON) Thread 2 (unmap)
> ------------------------------- -----------------
> madvise_inject_error()
> get_user_pages_fast() <- refcount++
> memory_failure(MF_COUNT_INCREASED)
> get_huge_page_for_hwpoison()
> spin_lock_irq(&hugetlb_lock)
> // refcount == 2 (gup + map)
> // MF_COUNT_INCREASED path:
> count_increased = true
> zap_pte_range()
> page_remove_rmap()
> put_page() <- drops map ref
> // refcount: 2 -> 1
Ok, bear with me.
I am not saying the change itself is wrong (maybe it is not), but how we ended
up in zap_pte_range() for a hugetlb folio?
The stacktrace does not seem to have much sense?
--
Oscar Salvador
SUSE Labs
next prev parent reply other threads:[~2026-05-20 8:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-20 2:01 [PATCH v3] mm/memory-failure: fix hugetlb_lock AA deadlock in get_huge_page_for_hwpoison Wupeng Ma
2026-05-20 2:40 ` Kefeng Wang
2026-05-20 2:45 ` mawupeng
2026-05-20 8:13 ` Oscar Salvador (SUSE) [this message]
2026-05-20 10:38 ` David Hildenbrand (Arm)
2026-05-20 11:24 ` mawupeng
2026-05-21 8:48 ` Oscar Salvador (SUSE)
2026-05-21 9:03 ` mawupeng
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