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Shutemov" Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , Andy Lutomirski , Peter Zijlstra , Ard Biesheuvel , Jan Kiszka , Kieran Bingham , Michael Roth , Rick Edgecombe , Brijesh Singh , Sandipan Das , Juergen Gross , Tom Lendacky , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds Subject: Re: [PATCHv3 0/4] x86: Make 5-level paging support unconditional for x86-64 Message-ID: References: <20250516123306.3812286-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250516123306.3812286-1-kirill.shutemov@linux.intel.com> X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: A3B4FA0009 X-Stat-Signature: hyq5ehphqg7aa8x3ya5co49m6ex6y9c7 X-Rspam-User: X-HE-Tag: 1747401082-613275 X-HE-Meta: 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 4U9rnOWJ vYsEZwgG+vp7fYbbOZT0RdqJbstsNlsxQN62YsOd11TsKPCy6daVN3pigSxGzZyqNPI0Bp0fZtns8jkSGWnQgPv2HGGIkoBOJzz6T4WFImupxyrWznwriLTS9GFlfpA00PDjpBgLjTuciESbct+ZcRivYbA5BvYanNKzAzZjl8X6gV9cyBf3XChNGT+oa4b0NtW72Vs5T6cFyDBD/FE73mveXiNrukw/7esdwWSwDFvt7vfw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: * Kirill A. Shutemov wrote: > Both Intel and AMD CPUs support 5-level paging, which is expected to > become more widely adopted in the future. > > Remove CONFIG_X86_5LEVEL. > > In preparation to that remove CONFIG_DYNAMIC_MEMORY_LAYOUT and make > SPARSEMEM_VMEMMAP the only memory model. > > v3: > - Drop few "#if CONFIG_PGTABLE_LEVELS >= 5"; > - Make PARAVIRT_XXL 64-bit explicitly and drop ifdefs > to support PGTABLE_LEVELS < 5; > - Add Reviewed-by tags from Ard; > v2: > - Fix 32-bit build by wrapping p4d_set_huge() and p4d_clear_huge() in > #if CONFIG_PGTABLE_LEVELS > 4; > - Rebased onto current tip/master; Wow, -v1 was sent almost a year ago. :-) > Kirill A. Shutemov (4): > x86/64/mm: Always use dynamic memory layout > x86/64/mm: Make SPARSEMEM_VMEMMAP the only memory model > x86/64/mm: Make 5-level paging support unconditional > x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only > 24 files changed, 14 insertions(+), 142 deletions(-) Okay, this series makes a lot of sense, because in practice all major distros have 5-level paging enabled: .config.opensuse.default: CONFIG_X86_5LEVEL=y .config.ubuntu.localinstall: CONFIG_X86_5LEVEL=y .config.fedora.generic: CONFIG_X86_5LEVEL=y .config.rhel.generic: CONFIG_X86_5LEVEL=y So the !CONFIG_X86_5LEVEL case gets very little runtime testing by distributions and users. So I've applied the first two patches to tip:x86/core: x86/mm/64: Always use dynamic memory layout x86/mm/64: Make SPARSEMEM_VMEMMAP the only memory model as they are fairly straightforward. Patch #3: x86/64/mm: Make 5-level paging support unconditional ... might have to wait until after v6.16-rc1, as it's a higher risk patch. x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only ... and this one depends on patch #3. Does this approach sound good to everyone? Thanks, Ingo