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Message-ID: <ba5a528d-7e85-77a2-5096-5a143a3b1606@linaro.org>
Date:   Mon, 2 Oct 2023 11:57:10 +0200
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Subject: Re: [PATCH v6 2/8] hugetlb: restructure pool allocations
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To:     Mike Kravetz <mike.kravetz@oracle.com>,
        Konrad Dybcio <konradybcio@kernel.org>
Cc:     Anshuman Khandual <anshuman.khandual@arm.com>,
        Xiongchun Duan <duanxiongchun@bytedance.com>,
        Barry Song <21cnbao@gmail.com>,
        David Rientjes <rientjes@google.com>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Matthew Wilcox <willy@infradead.org>, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Naoya Horiguchi <naoya.horiguchi@linux.dev>,
        Joao Martins <joao.m.martins@oracle.com>,
        David Hildenbrand <david@redhat.com>,
        Michal Hocko <mhocko@suse.com>,
        Oscar Salvador <osalvador@suse.de>,
        linux-kernel@vger.kernel.org
References: <20230925234837.86786-3-mike.kravetz@oracle.com>
 <ddc10c41-515f-48c9-966d-4ae7756d208c@kernel.org>
 <20230929205731.GA10357@monkey>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <20230929205731.GA10357@monkey>
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On 9/29/23 22:57, Mike Kravetz wrote:
> On 09/27/23 13:26, Konrad Dybcio wrote:
>>
>>
>> On 26.09.2023 01:48, Mike Kravetz wrote:
>>> Allocation of a hugetlb page for the hugetlb pool is done by the routine
>>> alloc_pool_huge_page.  This routine will allocate contiguous pages from
>>> a low level allocator, prep the pages for usage as a hugetlb page and
>>> then add the resulting hugetlb page to the pool.
>>>
>>> In the 'prep' stage, optional vmemmap optimization is done.  For
>>> performance reasons we want to perform vmemmap optimization on multiple
>>> hugetlb pages at once.  To do this, restructure the hugetlb pool
>>> allocation code such that vmemmap optimization can be isolated and later
>>> batched.
>>>
>>> The code to allocate hugetlb pages from bootmem was also modified to
>>> allow batching.
>>>
>>> No functional changes, only code restructure.
>>>
>>> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
>>> Reviewed-by: Muchun Song <songmuchun@bytedance.com>
>>> ---
>> Hi, looks like this patch prevents today's next from booting
>> on at least one Qualcomm ARM64 platform. Reverting it makes
>> the device boot again.
> 
> Can you share the config used and any other specific information such as
> kernel command line.
Later this week.

Konrad