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References: <20220630043237.2059576-1-chenhuacai@loongson.cn> <20220630043237.2059576-4-chenhuacai@loongson.cn>
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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 30 Jun 2022 08:05:04 +0200
Message-ID: <CAK8P3a1f94z4oSnMr73PuiXkMR7uGhthzY_EWVniB+G4KXBcBQ@mail.gmail.com>
Subject: Re: [PATCH V2 3/4] mm/sparse-vmemmap: Generalise vmemmap_populate_hugepages()
To:     Huacai Chen <chenhuacai@loongson.cn>
Cc:     Arnd Bergmann <arnd@arndb.de>, Huacai Chen <chenhuacai@kernel.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, loongarch@lists.linux.dev,
        linux-arch <linux-arch@vger.kernel.org>,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Guo Ren <guoren@kernel.org>, Xuerui Wang <kernel@xen0n.name>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux-MM <linux-mm@kvack.org>,
        "open list:BROADCOM NVRAM DRIVER" <linux-mips@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Feiyang Chen <chenfeiyang@loongson.cn>
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On Thu, Jun 30, 2022 at 6:32 AM Huacai Chen <chenhuacai@loongson.cn> wrote:
>
> From: Feiyang Chen <chenfeiyang@loongson.cn>
>
> Generalise vmemmap_populate_hugepages() so ARM64 & X86 & LoongArch can
> share its implementation.

Sharing this function is good, thanks for consolidating this

> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>

The Signed-off-by lines are in the wrong order, it should start with the author
and end with the final submitter.

> index 33e2a1ceee72..6f2e40bb695d 100644
> --- a/mm/sparse-vmemmap.c
> +++ b/mm/sparse-vmemmap.c
> @@ -686,6 +686,60 @@ int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
>         return vmemmap_populate_range(start, end, node, altmap, NULL);
>  }
>
> +void __weak __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
> +                                     unsigned long addr, unsigned long next)
> +{
> +}
> +
> +int __weak __meminit vmemmap_check_pmd(pmd_t *pmd, int node, unsigned long addr,
> +                                      unsigned long next)
> +{
> +       return 0;
> +}
> +

I think inline functions would be better here, both for compiler optimization
and to make it easier to track the code flow. The normal way we do these
in architecture specific headers is to override the functions by defining a
macro of the same name.


        Arnd