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 <20211018123710.1540996-2-chenwandun@huawei.com> <YW1rEt0u2CSCYgnJ@casper.infradead.org>
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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 19 Oct 2021 08:53:58 -0700
Message-ID: <CALvZod4BEu3sYuo3kZ9OS0SXHm_q7C8w7sYObJo9X_xeMUd8sQ@mail.gmail.com>
Subject: Re: [PATCH v2 1/2] mm/vmalloc: fix numa spreading for large hash tables
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Chen Wandun <chenwandun@huawei.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>, guohanjun@huawei.com,
        "Uladzislau Rezki (Sony)" <urezki@gmail.com>
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On Mon, Oct 18, 2021 at 5:41 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> 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?

I agree with Willy's suggestion to make it more explicit but as a
followup work. This patch needs a backport, so keep this simple.