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Date:   Wed, 18 Oct 2023 19:38:40 -0700
From:   Mike Kravetz <mike.kravetz@oracle.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Usama Arif <usama.arif@bytedance.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        muchun.song@linux.dev, songmuchun@bytedance.com,
        fam.zheng@bytedance.com, liangma@liangbit.com,
        punit.agrawal@bytedance.com
Subject: Re: [PATCH] mm: hugetlb: Only prep and add allocated folios for
 non-gigantic pages
Message-ID: <20231019023840.GA345531@monkey>
References: <20231009145605.2150897-1-usama.arif@bytedance.com>
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On 10/09/23 15:56, Usama Arif wrote:
> Calling prep_and_add_allocated_folios when allocating gigantic pages
> at boot time causes the kernel to crash as folio_list is empty
> and iterating it causes a NULL pointer dereference. Call this only
> for non-gigantic pages when folio_list has entires.
> 
> Fixes: bfb41d6b2fe148 ("hugetlb: restructure pool allocations")
> Signed-off-by: Usama Arif <usama.arif@bytedance.com>
> ---
>  mm/hugetlb.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Hi Andrew,

Can you remove this from mm-unstable.  The root cause of Usama's crash
was improper irq enablement via locking calls.  The changes Usama
verified (later in this thread) are in v8 of the "Batch hugetlb vmemmap
modification operations" series I just sent.
-- 
Mike Kravetz