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Date:   Mon, 27 Jun 2022 17:58:50 +0530
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Subject: Re: [RFC PATCH 05/26] hugetlb: add
 CONFIG_HUGETLB_HIGH_GRANULARITY_MAPPING
To:     James Houghton <jthoughton@google.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Peter Xu <peterx@redhat.com>
Cc:     David Hildenbrand <david@redhat.com>,
        David Rientjes <rientjes@google.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Mina Almasry <almasrymina@google.com>,
        Jue Wang <juew@google.com>,
        "Dr . David Alan Gilbert" <dgilbert@redhat.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220624173656.2033256-1-jthoughton@google.com>
 <20220624173656.2033256-6-jthoughton@google.com>
From:   "manish.mishra" <manish.mishra@nutanix.com>
In-Reply-To: <20220624173656.2033256-6-jthoughton@google.com>
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On 24/06/22 11:06 pm, James Houghton wrote:
> This adds the Kconfig to enable or disable high-granularity mapping. It
> is enabled by default for architectures that use
> ARCH_WANT_GENERAL_HUGETLB.
>
> There is also an arch-specific config ARCH_HAS_SPECIAL_HUGETLB_HGM which
> controls whether or not the architecture has been updated to support
> HGM if it doesn't use general HugeTLB.
>
> Signed-off-by: James Houghton <jthoughton@google.com>
reviewed-by:manish.mishra@nutanix.com
> ---
>   fs/Kconfig | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 5976eb33535f..d76c7d812656 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -268,6 +268,13 @@ config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON
>   	  to enable optimizing vmemmap pages of HugeTLB by default. It can then
>   	  be disabled on the command line via hugetlb_free_vmemmap=off.
>   
> +config ARCH_HAS_SPECIAL_HUGETLB_HGM
> +	bool
> +
> +config HUGETLB_HIGH_GRANULARITY_MAPPING
> +	def_bool ARCH_WANT_GENERAL_HUGETLB || ARCH_HAS_SPECIAL_HUGETLB_HGM
> +	depends on HUGETLB_PAGE
> +
>   config MEMFD_CREATE
>   	def_bool TMPFS || HUGETLBFS
>