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Message-ID: <6e310e59-c0b6-5ba2-f927-7754c3e9e941@huawei.com>
Date:   Mon, 18 Oct 2021 21:01:01 +0800
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Subject: Re: [PATCH v2 1/2] mm/vmalloc: fix numa spreading for large hash
 tables
To:     Matthew Wilcox <willy@infradead.org>
CC:     <akpm@linux-foundation.org>, <npiggin@gmail.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <edumazet@google.com>, <wangkefeng.wang@huawei.com>,
        <guohanjun@huawei.com>, <shakeelb@google.com>, <urezki@gmail.com>
References: <20211018123710.1540996-1-chenwandun@huawei.com>
 <20211018123710.1540996-2-chenwandun@huawei.com>
 <YW1rEt0u2CSCYgnJ@casper.infradead.org>
From:   Chen Wandun <chenwandun@huawei.com>
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在 2021/10/18 20:39, Matthew Wilcox 写道:
> On Mon, Oct 18, 2021 at 08:37:09PM +0800, Chen Wandun wrote:
>> Eric Dumazet reported a strange numa spreading info in [1], and found
>> commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") introduced
>> this issue [2].
> 
> I think the root problem here is that we have two meanings for
> NUMA_NO_NODE.  I tend to read it as "The memory can be allocated from
> any node", but here it's used to mean "The memory should be spread over
> every node".  Should we split those out as -1 and -2?
Yes, the intent of NUMA_NO_NODE some time is confused.

Besides，I think NUMA_NO_NODE should consider mempolicy in
most cases in the kernel unless it point out explicitly memory
can be allocated without considering mempolicy.

> .
>