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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 5 Jul 2022 10:45:06 +0200
Message-ID: <CAK8P3a1K9fmLK=dh8shHX2y=fOYzr02D9Ek9uQri-u_2MsBXdQ@mail.gmail.com>
Subject: Re: [PATCH V4 4/4] LoongArch: Enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     Arnd Bergmann <arnd@arndb.de>, Huacai Chen <chenhuacai@kernel.org>,
        Huacai Chen <chenhuacai@loongson.cn>,
        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 Tue, Jul 5, 2022 at 10:38 AM Muchun Song <songmuchun@bytedance.com> wrote:
> On Tue, Jul 5, 2022 at 4:06 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > On Tue, Jul 5, 2022 at 9:51 AM Muchun Song <songmuchun@bytedance.com> wrote:
>
> How about including the static key header in the scope of
> CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP?

That helps a little, but it means we still pay for it on x86 and
arm64, which are the
most common architectures.

       Arnd