Date:   Mon, 13 Feb 2023 10:53:18 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Qi Zheng <zhengqi.arch@bytedance.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: page_alloc: call panic() when memoryless node
 allocation fails
Message-Id: <20230213105318.e2a83d60c12e734d45dccf1a@linux-foundation.org>
In-Reply-To: <20230212111027.95520-1-zhengqi.arch@bytedance.com>
References: <20230212111027.95520-1-zhengqi.arch@bytedance.com>
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On Sun, 12 Feb 2023 19:10:27 +0800 Qi Zheng <zhengqi.arch@bytedance.com> wrote:

> In free_area_init(), we will continue to run after pgdat of memoryless
> node allocation fails. However, in the subsequent process (such as when
> initializing zonelist), the case that NODE_DATA(nid) is NULL is not
> handled, which will cause panic. Instead of this, it's better to call
> panic() directly when the memory allocation fails during system boot.
> 
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8360,11 +8360,9 @@ void __init free_area_init(unsigned long *max_zone_pfn)
>  
>  			/* Allocator not initialized yet */
>  			pgdat = arch_alloc_nodedata(nid);
> -			if (!pgdat) {
> -				pr_err("Cannot allocate %zuB for node %d.\n",
> -						sizeof(*pgdat), nid);
> -				continue;
> -			}
> +			if (!pgdat)
> +				panic("Cannot allocate %zuB for node %d.\n",
> +				       sizeof(*pgdat), nid);
>  			arch_refresh_nodedata(nid, pgdat);
>  			free_area_init_memoryless_node(nid);

Have you actually hit this at runtime?  If so, is there something we
can do to handle this failure more gracefully?