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Subject: Re: [PATCH v2] mm/hugetlb: fix DEBUG_LOCKS_WARN_ON(1) when
 dissolve_free_hugetlb_folio()
To: Andrew Morton <akpm@linux-foundation.org>
CC: <muchun.song@linux.dev>, <mike.kravetz@oracle.com>, <osalvador@suse.de>,
	<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
References: <20240419085819.1901645-1-linmiaohe@huawei.com>
 <20240419141134.464ea3a1ef3d0e93c6711c93@linux-foundation.org>
 <000d75f3-6e16-6b91-7657-afb954773381@huawei.com>
 <20240422142115.25582386f7f02df817eab8ae@linux-foundation.org>
From: Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <7364e90a-1a55-21da-b579-52e7396fe266@huawei.com>
Date: Tue, 23 Apr 2024 11:56:34 +0800
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On 2024/4/23 5:21, Andrew Morton wrote:
> On Sat, 20 Apr 2024 10:13:06 +0800 Miaohe Lin <linmiaohe@huawei.com> wrote:
> 
>> On 2024/4/20 5:11, Andrew Morton wrote:
>>> On Fri, 19 Apr 2024 16:58:19 +0800 Miaohe Lin <linmiaohe@huawei.com> wrote:
>>>
>>>> When I did memory failure tests recently, below warning occurs:
>>>>
>>>> DEBUG_LOCKS_WARN_ON(1)
>>>> WARNING: CPU: 8 PID: 1011 at kernel/locking/lockdep.c:232 __lock_acquire+0xccb/0x1ca0
>>>> Modules linked in: mce_inject hwpoison_inject
>>>> CPU: 8 PID: 1011 Comm: bash Kdump: loaded Not tainted 6.9.0-rc3-next-20240410-00012-gdb69f219f4be #3
>>>>
>>>> ...
>>>>
>>>> --- a/mm/hugetlb.c
>>>> +++ b/mm/hugetlb.c
>>>> @@ -1773,7 +1773,7 @@ static void __update_and_free_hugetlb_folio(struct hstate *h,
>>>>  	 * If vmemmap pages were allocated above, then we need to clear the
>>>>  	 * hugetlb flag under the hugetlb lock.
>>>>  	 */
>>>> -	if (clear_flag) {
>>>> +	if (folio_test_hugetlb(folio)) {
>>>>  		spin_lock_irq(&hugetlb_lock);
>>>>  		__folio_clear_hugetlb(folio);
>>>>  		spin_unlock_irq(&hugetlb_lock);
>>>
>>> Please let's prepare backportable fixes against current mainline, not
>>> mm-unstable.  Because fixes against current -rcX and earlier will be
>>> upstreamed ahead of the mm-unstable and mm-stable material.
>>
>> Do you mean I need to send one fixup patch against mm-unstable and another
>> one against current mainline?
> 
> Against mainline should suffice.  I normally fix up the subsequent
> merge/build fallout.  If that gets too risky I'll ask for help or I'll
> outright drop mm-unstable patches and shall ask for a redo of those. 
> This is rare.

I see. Many thanks for your explanation. :)
Thanks.
.

> 
> .
>