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bh=n2wKaJ7B0u+TOzRiWJjt2/jNzta6bxVIi/vLveRb+xM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EhPcYTo21sYUZH9+m6BG3jc3jRms3MDajrKqMQo3+J/Br/TT7Bx5wZisHVwYpinRs vNmVPG9EUiMlKE4qll0V0DRk3wH2LxO3ltS9xRWlXNM6ILTsIElFg6wNQGUWdjxH6M kKgzNHLQgUyEWcTSuxQrpZEPjKeGAT6HYZ7x/QZs= Date: Tue, 18 Aug 2026 15:16:07 +0100 From: Catalin Marinas To: James Houghton Cc: Will Deacon , Muchun Song , Oscar Salvador , Nikos Nikoleris , Linu Cherian , Mark Rutland , David Hildenbrand , Andrew Morton , Ryan Roberts , Nanyong Sun , Yu Zhao , Frank van der Linden , David Rientjes , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Subject: Re: [PATCH 10/18] arm64: Support hugetlb vmemmap optimization Message-ID: References: <20260708031129.3503195-1-jthoughton@google.com> <20260708031129.3503195-11-jthoughton@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260708031129.3503195-11-jthoughton@google.com> X-Rspam-User: X-Stat-Signature: no9gr16pbe4iduznx1spyy9tpxp9z53u X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 55557140013 X-HE-Tag: 1787062581-313044 X-HE-Meta: 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 4vr7pIvI Ho9dQUHFDM3IdYBEfXYkPp6g9SHl3AGwxaQ1E2DPUzMBllkwLEYa2zK6YFKAlJNbUurf6mya/oazNcuxtrxGsTf5MgR9BUmIPgM3fAGThGcfciwSYe5iB48Il0BjAAWjn9XM7PSE8QdJNlWJRow7GzVfMitCv/ir4UXYsUClAgrs48WqwswTu3CqKilHEMwIRiVGiz8SLH3dEo8MCeey6fFGypBIr3FWzjMyGfR4jL/kA/XE= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Jul 08, 2026 at 03:11:20AM +0000, James Houghton wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index b3afe0688919..cf4bd6bd7f11 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -259,6 +259,7 @@ config ARM64 > select USER_STACKTRACE_SUPPORT > select VDSO_GETRANDOM > select VMAP_STACK > + select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if ARM64_WANT_OPTIMIZE_HUGETLB_VMEMMAP Nit: we try to keep this list alphabetically ordered. > help > ARM 64-bit (AArch64) Linux support. > > @@ -1607,6 +1608,17 @@ config ARCH_SPARSEMEM_ENABLE > def_bool y > select SPARSEMEM_VMEMMAP_ENABLE > > +config ARM64_WANT_OPTIMIZE_HUGETLB_VMEMMAP > + bool "Enable support for HugeTLB Vmemmap Optimization (HVO)" > + default n Nit: 'n' is the default already. > + depends on HUGETLB_PAGE && SPARSEMEM_VMEMMAP && ARM64_HW_AFDBM > + help > + Enable support for HVO. When enabled, late-onlining of CPUs that do I'd drop 'of', not sure how it reads better. Maybe just 'late CPUs ... will not be onlined'. > + not support features required by HVO will not be onlined if all boot > + CPUs do have such support. > + > + If unsure, say N > + > config HW_PERF_EVENTS > def_bool y > depends on ARM_PMU -- Catalin