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Message-ID: <b1975f44-2552-a03c-bb6f-1452f1fd99c0@redhat.com>
Date:   Tue, 7 Jun 2022 14:25:47 +0200
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Subject: Re: [PATCH v3 4/6] mm: Demote warning message in vmemmap_verify() to
 debug level
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To:     Wupeng Ma <mawupeng1@huawei.com>, corbet@lwn.net, will@kernel.org,
        ardb@kernel.org, catalin.marinas@arm.com
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        dvhart@infradead.org, andy@infradead.org, rppt@kernel.org,
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        palmer@dabbelt.com, aou@eecs.berkeley.edu, paulmck@kernel.org,
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        anshuman.khandual@arm.com, thunder.leizhen@huawei.com,
        wangkefeng.wang@huawei.com, gpiccoli@igalia.com,
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References: <20220607093805.1354256-1-mawupeng1@huawei.com>
 <20220607093805.1354256-5-mawupeng1@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20220607093805.1354256-5-mawupeng1@huawei.com>
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On 07.06.22 11:38, Wupeng Ma wrote:
> From: Ma Wupeng <mawupeng1@huawei.com>
> 
> For a system only have limited mirrored memory or some numa node without
> mirrored memory, the per node vmemmap page_structs prefer to allocate
> memory from mirrored region, which will lead to vmemmap_verify() in
> vmemmap_populate_basepages() report lots of warning message.
> 
> This patch demote the "potential offnode page_structs" warning messages
> to debug level to avoid a very long print during bootup.
> 
> Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
> ---
>  mm/sparse-vmemmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
> index f4fa61dbbee3..78debdb89eb1 100644
> --- a/mm/sparse-vmemmap.c
> +++ b/mm/sparse-vmemmap.c
> @@ -528,7 +528,7 @@ void __meminit vmemmap_verify(pte_t *pte, int node,
>  	int actual_node = early_pfn_to_nid(pfn);
>  
>  	if (node_distance(actual_node, node) > LOCAL_DISTANCE)
> -		pr_warn("[%lx-%lx] potential offnode page_structs\n",
> +		pr_debug("[%lx-%lx] potential offnode page_structs\n",
>  			start, end - 1);
>  }
>  

This will possibly hide it in environments where this might indeed
indicate performance issues.

What about a pr_warn_once()?

-- 
Thanks,

David / dhildenb