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Date:   Fri, 29 Apr 2022 11:30:36 +0200
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Subject: Re: [PATCH v3 2/4] hugetlb: Fix hugepages_setup when deal with
 pernode
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To:     Peng Liu <liupeng256@huawei.com>, mike.kravetz@oracle.com,
        akpm@linux-foundation.org, yaozhenguo1@gmail.com,
        baolin.wang@linux.alibaba.com, songmuchun@bytedance.com,
        liuyuntao10@huawei.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20220413032915.251254-1-liupeng256@huawei.com>
 <20220413032915.251254-3-liupeng256@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20220413032915.251254-3-liupeng256@huawei.com>
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On 13.04.22 05:29, Peng Liu wrote:
> Hugepages can be specified to pernode since "hugetlbfs: extend
> the definition of hugepages parameter to support node allocation",
> but the following problem is observed.
> 
> Confusing behavior is observed when both 1G and 2M hugepage is set
> after "numa=off".
>  cmdline hugepage settings:
>   hugepagesz=1G hugepages=0:3,1:3
>   hugepagesz=2M hugepages=0:1024,1:1024
>  results:
>   HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages
>   HugeTLB registered 2.00 MiB page size, pre-allocated 1024 pages
> 
> Furthermore, confusing behavior can be also observed when an
> invalid node behind a valid node. To fix this, never allocate any
> typical hugepage when an invalid parameter is received.
> 
> Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
> Signed-off-by: Peng Liu <liupeng256@huawei.com>
> ---
>  mm/hugetlb.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 5b5a2a5a742f..1930b6341f7e 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4116,6 +4116,20 @@ bool __init __weak hugetlb_node_alloc_supported(void)
>  {
>  	return true;
>  }
> +
> +static void __init hugepages_clear_pages_in_node(void)

I think the name is a bit imprecise, but I have no better suggestion
right now.

Reviewed-by: David Hildenbrand <david@redhat.com>


-- 
Thanks,

David / dhildenb