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From: Muchun Song In-Reply-To: Date: Tue, 28 Apr 2026 19:40:43 +0800 Cc: Muchun Song , Vishal Verma , Ying Huang , Dan Williams , Naoya Horiguchi , linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, David Hildenbrand , Oscar Salvador , Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , Andrew Morton Content-Transfer-Encoding: quoted-printable Message-Id: <68DFF29C-B3CC-4950-8A8E-7D42350939CA@linux.dev> References: <20260428085219.1316047-1-songmuchun@bytedance.com> <20260428085219.1316047-4-songmuchun@bytedance.com> To: Miaohe Lin X-Migadu-Flow: FLOW_OUT X-Stat-Signature: zfcg7ui1mtngnoxoqdr3tn7xcy4yoc6b X-Rspam-User: X-Rspamd-Queue-Id: AA0BFC000B X-Rspamd-Server: rspam07 X-HE-Tag: 1777376491-753286 X-HE-Meta: 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 r0ty/vkN mKR0pCZHDw3rPhK1v655Hy5OsRwKwMQwgwaD2YGT9Vvy3LrbzXgI90xlk8XLzMWC9CopXXAU6FFa0RUI4AO/3s4jFY3AJqvBabQwNXmQZkfW0G/UfeQmai6NoTy5ZN1YTT/dJQBcZRUYAEYXs/LPdbRq28pfzNswjXa/o5o4EToCeqHQ08aCLK1Z7gMaWHR+MHIvgAsJeFrWEpg6G2Z7j3IyvFWMgz8/QlHOX/hp8j9VrQdEQtZYzz/S4CIek7DMHpOHvdTsJF7ife+SR2+m14JKpUA/3T0eyFF5+da879Oqj9raHDINvWry33Hl0ztXIb61iWuZXxBqWkcB8+DXrk9Bym2SzkkDxOyaWlM5jHMgqF6sMObwTpJ4Vh2pPZw59hVLG Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Apr 28, 2026, at 19:37, Miaohe Lin wrote: >=20 > On 2026/4/28 16:52, Muchun Song wrote: >> memblk_nr_poison_inc() and memblk_nr_poison_sub() call >> find_memory_block_by_id(), which requires device_hotplug_lock to >> serialize the xarray lookup against memory block removal. >>=20 >> Take device_hotplug_lock around the lookup and nr_hwpoison update so >> the memory block cannot disappear between xa_load() and get_device(). >>=20 >> Fixes: 5033091de814 ("mm/hwpoison: introduce per-memory_block = hwpoison counter") >> Cc: stable@vger.kernel.org >> Signed-off-by: Muchun Song >=20 > Thanks for update. >=20 >> --- >> drivers/base/memory.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >>=20 >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index 6981b55d582a..f76aee29e9a5 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -1228,23 +1228,29 @@ int walk_dynamic_memory_groups(int nid, = walk_memory_groups_func_t func, >> void memblk_nr_poison_inc(unsigned long pfn) >> { >> const unsigned long block_id =3D pfn_to_block_id(pfn); >> - struct memory_block *mem =3D find_memory_block_by_id(block_id); >> + struct memory_block *mem; >>=20 >> + lock_device_hotplug(); >=20 > memblk_nr_poison_inc() and memblk_nr_poison_sub() are both called from = memory_failure() context. > I'm afraid if memory_failure() is triggered while lock_device_hotplug = is held, it will lead to > deadlock. Or am I miss something? I am curious is there any place where memory_failure() is called with = holding lock_device_hotplug? Thanks. >=20 > Thanks. > .