From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout08.his.huawei.com (canpmsgout08.his.huawei.com [113.46.200.223]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEACF3ACA6A; Tue, 28 Apr 2026 11:37:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.223 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777376249; cv=none; b=dLOcagCEeyxCqNlUDPJQMfbxP0cxlU3tMob2M4hgsncrUpEHwNBmEoqGxhRCoYPoJ9Bsood1Po45w6T9LKl3F3TbvTdMVLDa73USOizjSqzyXFpwwWb5A5Koa/+5PtxdwmZdXFFmFSePzP95tJNpsfHeMgxHpRyNFF0C8/kqYfc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777376249; c=relaxed/simple; bh=cIhFdiuC/sLMm2BsvD39eZ3qa9Yt1htop66XZgtLjHA=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=epFHqDV1myhrWExbcl4oYxXMukX/kRaRWQftuxpRnDzOO7BqA5kGba57QVySIIsazS8Xhu0AcA17NqtZvkkHBzD8DJNJw9X7PIAJ3FpWQkdGUgg66yhR/g+dAUWeE0Ucb4cVAMKweta4Z+nTakNasVgZqJFJP6KzO0O+oVgBeg0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=v0bFUI0B; arc=none smtp.client-ip=113.46.200.223 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="v0bFUI0B" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=yP5OQNhMmcwIxI1oI5Mx5fKdBBjTBBmIQZkVZovEd3g=; b=v0bFUI0BEOyWueLy7pxnHCOKVoR0igzwxlVGdMA0Qyw81uWFz3SqQ8IPZMcyLRX01XUCsllDq buzpaLWGFTiho+PSVkEx0QUmIuhhGNY9chtIZr3xID27VtEzn6XPzSqZ2zQ1nG4KdfnWkjZEDqE lN3A5Uglgi494HwPD5AeF4k= Received: from mail.maildlp.com (unknown [172.19.162.92]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4g4dXv4h6bzmV6X; Tue, 28 Apr 2026 19:30:55 +0800 (CST) Received: from dggemv705-chm.china.huawei.com (unknown [10.3.19.32]) by mail.maildlp.com (Postfix) with ESMTPS id 7998540565; Tue, 28 Apr 2026 19:37:23 +0800 (CST) Received: from kwepemq500010.china.huawei.com (7.202.194.235) by dggemv705-chm.china.huawei.com (10.3.19.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 28 Apr 2026 19:37:23 +0800 Received: from [10.173.124.160] (10.173.124.160) by kwepemq500010.china.huawei.com (7.202.194.235) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 28 Apr 2026 19:37:22 +0800 Subject: Re: [PATCH v2 3/3] drivers/base/memory: fix locking for poison accounting lookup To: Muchun Song CC: Vishal Verma , Ying Huang , Dan Williams , "Naoya Horiguchi" , , , , , , , David Hildenbrand , Oscar Salvador , Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , "Andrew Morton" References: <20260428085219.1316047-1-songmuchun@bytedance.com> <20260428085219.1316047-4-songmuchun@bytedance.com> From: Miaohe Lin Message-ID: Date: Tue, 28 Apr 2026 19:37:21 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20260428085219.1316047-4-songmuchun@bytedance.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemq500010.china.huawei.com (7.202.194.235) 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. > > Take device_hotplug_lock around the lookup and nr_hwpoison update so > the memory block cannot disappear between xa_load() and get_device(). > > Fixes: 5033091de814 ("mm/hwpoison: introduce per-memory_block hwpoison counter") > Cc: stable@vger.kernel.org > Signed-off-by: Muchun Song Thanks for update. > --- > drivers/base/memory.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > 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 = pfn_to_block_id(pfn); > - struct memory_block *mem = find_memory_block_by_id(block_id); > + struct memory_block *mem; > > + lock_device_hotplug(); 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? Thanks. .