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Subject: Re: [PATCH] MIPS: Loongson: Fix complie errors without CONFIG_SMP
To:     Matthew Wilcox <willy@infradead.org>
References: <1598446407-8845-1-git-send-email-hejinyang@loongson.cn>
 <20200826130122.GR17456@casper.infradead.org>
Cc:     Huacai Chen <chenhc@lemote.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Tiezhu Yang <yangtiezhu@loongson.cn>,
        Xuefeng Li <lixuefeng@loongson.cn>
From:   hejinyang <hejinyang@loongson.cn>
Message-ID: <5394f030-104c-f191-e581-4f1ed23a85a6@loongson.cn>
Date:   Thu, 27 Aug 2020 10:31:33 +0800
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On 08/26/2020 09:01 PM, Matthew Wilcox wrote:
> On Wed, Aug 26, 2020 at 08:53:27PM +0800, Jinyang He wrote:
>> +++ b/arch/mips/include/asm/mach-loongson64/topology.h
>> @@ -4,7 +4,11 @@
>>   
>>   #ifdef CONFIG_NUMA
>>   
>> +#ifdef CONFIG_SMP
>>   #define cpu_to_node(cpu)	(cpu_logical_map(cpu) >> 2)
>> +#else
>> +#define cpu_to_node(cpu)	0
>> +#endif
> Are you saying you've enabled NUMA without enabling SMP?  Does that make
> sense?

NUMA option normally work with more than two nodes, though Loongson64 use it
default after patch 6fbde6b492dfc761ad60a68fb2cb32b1eb05b786. Loongson64(3A)'s
each node consists of 4 cpus while it only has 4 cpus. In other words, it has
only one node while open NUMA. I'm confused it if NUMA deponds on SMP.

I'll try fix it with unabling NUMA and SMP later.

Thanks.:-)