From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f49.google.com (mail-qv1-f49.google.com [209.85.219.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A7E3D54658 for ; Sat, 19 Oct 2024 15:47:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729352862; cv=none; b=mFPF0vv2l75PkfStCDDa9caoEb8v99gRF+QrQaggbM3tb10UFAnvT3tZ4EdVrWirJSW5CbmJqvaLrmQme/2sqCLLSNLqsHAj9zXQeVFWGv5KLAGdsLt18pdbjzGaEd2IUQnilLfpYBQpNvLoWOG6T/n5LgEG7I+dBrX3vvwZowM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729352862; c=relaxed/simple; bh=qJlQ+zl4XtUjZJosCdACec8xj4oFX0I3CkBuV6WljoU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=AZA077wlDTdXHpjGEi1H5b4Fie/imKZJqzHG5QdzvmF+P03UsmotV9G/I50sYaQQfWA0apCsM1RaK4Yl4GmEct33XmAYgt8uXwyXueGICDjP9cXbs3gST9kHWCqo3DBFFoEpD8FIC3/wgmozto9Mea7BOc6TwLI3kMOP90WtdqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gompa.dev; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.219.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gompa.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-qv1-f49.google.com with SMTP id 6a1803df08f44-6cbf0e6414aso15395296d6.1 for ; Sat, 19 Oct 2024 08:47:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729352858; x=1729957658; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=G63xobObUesc+tM9grD0l6VEGTiBj9BEo7HxtoekjNA=; b=vgSvmNKGsQRa+3s190gv6m7MgrftrSoNLYMrYLbOJ0TpdSBHVUgusa54LXHC7M/QGi +gVlpcou/5+UzriNKvDRd8obaP3KQ33v6Wl2j7PPQlKuHRiWlisPdaZLbH4DloarboDB FwslTDazaxWdMVEwrww4OD9202oCyb1/nou++uvKjOVWVT1/UULpRWOq4BKwMeXWIHO2 ZuCLOtr4l2yfkWZFgcuQcLlYFg1UL4/fXiMJOq0cnE3lkvmbZhYNWFiJN5v4A9sFeKlf BPry7WwFuecS+w0prDz79Lf81PlQ0QrbvpL0qkg/54G47jjTlglFd4HVy+W+fsPmeD9B EBOQ== X-Forwarded-Encrypted: i=1; AJvYcCUJ+5+4j3zKfxhusP/OM5xTwHpxR5a3YoGZFSyl085g7I5gKgo45DVGVeqoiTvgYw8nGpTL/zdnMq1ZxuQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxptGIHRtnvIx5AqMzkUVscgrQDoccylC2fH4ip66SMQ6SuOvmu T0kVmJvzYZVu0dCDJYJ2GEiiMvz3KNtHIS6FgZwNUKKNENwO0gO2 X-Google-Smtp-Source: AGHT+IFk5vs8CBgIY3C58BlC36e3AOtR0tKDQAi06wW9c+mnI2No0EUOTL9dQ/0o2YRVe76+1QFapw== X-Received: by 2002:a05:6214:5a06:b0:6cc:4136:205 with SMTP id 6a1803df08f44-6cde1542a36mr87053666d6.26.1729352858255; Sat, 19 Oct 2024 08:47:38 -0700 (PDT) Received: from skuld-framework.localnet ([32.221.37.233]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6cde111b4c0sm20116796d6.18.2024.10.19.08.47.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Oct 2024 08:47:37 -0700 (PDT) From: Neal Gompa To: Andrew Morton , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Greg Marsden , Ivan Ivanov , Kalesh Singh , Marc Zyngier , Mark Rutland , Matthias Brugger , Miroslav Benes , Will Deacon , Ryan Roberts , Hector Martin Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, asahi@lists.linux.dev Subject: Re: [RFC PATCH v1 00/57] Boot-time page size selection for arm64 Date: Sat, 19 Oct 2024 11:47:35 -0400 Message-ID: <4623805.lGaqSPkdTl@skuld-framework> In-Reply-To: <20241014105514.3206191-1-ryan.roberts@arm.com> References: <20241014105514.3206191-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Monday, October 14, 2024 6:55:11=E2=80=AFAM EDT Ryan Roberts wrote: > Hi All, >=20 > Patch bomb incoming... This covers many subsystems, so I've included a co= re > set of people on the full series and additionally included maintainers on > relevant patches. I haven't included those maintainers on this cover lett= er > since the numbers were far too big for it to work. But I've included a li= nk > to this cover letter on each patch, so they can hopefully find their way > here. For follow up submissions I'll break it up by subsystem, but for now > thought it was important to show the full picture. >=20 > This RFC series implements support for boot-time page size selection with= in > the arm64 kernel. arm64 supports 3 base page sizes (4K, 16K, 64K), but to > date, page size has been selected at compile-time, meaning the size is > baked into a given kernel image. As use of larger-than-4K page sizes beco= me > more prevalent this starts to present a problem for distributions. > Boot-time page size selection enables the creation of a single kernel > image, which can be told which page size to use on the kernel command lin= e. >=20 > Why is having an image-per-page size problematic? > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > Many traditional distros are now supporting both 4K and 64K. And this mea= ns > managing 2 kernel packages, along with drivers for each. For some, it mea= ns > multiple installer flavours and multiple ISOs. All of this adds up to a > less-than-ideal level of complexity. Additionally, Android now supports 4K > and 16K kernels. I'm told having to explicitly manage their KABI for each > kernel is painful, and the extra flash space required for both kernel > images and the duplicated modules has been problematic. Boot-time page si= ze > selection solves all of this. >=20 > Additionally, in starting to think about the longer term deployment story > for D128 page tables, which Arm architecture now supports, a lot of the > same problems need to be solved, so this work sets us up nicely for that. >=20 > So what's the down side? > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > Well nothing's free; Various static allocations in the kernel image must = be > sized for the worst case (largest supported page size), so image size is = in > line with size of 64K compile-time image. So if you're interested in 4K or > 16K, there is a slight increase to the image size. But I expect that > problem goes away if you're compressing the image - its just some extra > zeros. At boot-time, I expect we could free the unused static storage once > we know the page size - although that would be a follow up enhancement. >=20 > And then there is performance. Since PAGE_SIZE and friends are no longer > compile-time constants, we must look up their values and do arithmetic at > runtime instead of compile-time. My early perf testing suggests this is > inperceptible for real-world workloads, and only has small impact on > microbenchmarks - more on this below. >=20 > Approach > =3D=3D=3D=3D=3D=3D=3D=3D >=20 > The basic idea is to rid the source of any assumptions that PAGE_SIZE and > friends are compile-time constant, but in a way that allows the compiler = to > perform the same optimizations as was previously being done if they do tu= rn > out to be compile-time constant. Where constants are required, we use > limits; PAGE_SIZE_MIN and PAGE_SIZE_MAX. See commit log in patch 1 for fu= ll > description of all the classes of problems to solve. >=20 > By default PAGE_SIZE_MIN=3DPAGE_SIZE_MAX=3DPAGE_SIZE. But an arch may opt= =2Din to > boot-time page size selection by defining PAGE_SIZE_MIN & PAGE_SIZE_MAX. > arm64 does this if the user selects the CONFIG_ARM64_BOOT_TIME_PAGE_SIZE > Kconfig, which is an alternative to selecting a compile-time page size. >=20 > When boot-time page size is active, the arch pgtable geometry macro > definitions resolve to something that can be configured at boot. The arm64 > implementation in this series mainly uses global, __ro_after_init > variables. I've tried using alternatives patching, but that performs worse > than loading from memory; I think due to code size bloat. >=20 > Status > =3D=3D=3D=3D=3D=3D >=20 > When CONFIG_ARM64_BOOT_TIME_PAGE_SIZE is selected, I've only implemented > enough to compile the kernel image itself with defconfig (and a few other > bits and pieces). This is enough to build a kernel that can boot under QE= MU > or FVP. I'll happily do the rest of the work to enable all the extra > drivers, but wanted to get feedback on the shape of this effort first. If > anyone wants to do any testing, and has a must-have config, let me know a= nd > I'll prioritize enabling it first. >=20 > The series is arranged as follows: >=20 > - patch 1: Add macros required for converting non-arch code to suppo= rt > boot-time page size selection > - patches 2-36: Remove PAGE_SIZE compile-time constant assumption from > all non-arch code > - patches 37-38: Some arm64 tidy ups > - patch 39: Add macros required for converting arm64 code to=20 support > boot-time page size selection > - patches 40-56: arm64 changes to support boot-time page size selection > - patch 57: Add arm64 Kconfig option to enable boot-time page=20 size > selection >=20 > Ideally, I'd like to get the basics merged (something like this series), > then incrementally improve it over a handful of kernel releases until we > can demonstrate that we have feature parity with the compile-time build a= nd > no performance blockers. Once at that point, ideally the compile-time bui= ld > options would be removed and the code could be cleaned up further. >=20 > One of the bigger peices that I'd propose to add as a follow up, is to ma= ke > va-size boot-time selectable too. That will greatly simplify LPA2 fallback > handling. >=20 > Assuming people are ammenable to the rough shape, how would I go about > getting the non-arch changes merged? Since they cover many subsystems, wi= ll > each piece need to go independently to each relevant maintainer or could = it > all be merged together through the arm64 tree? >=20 > Image Size > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > The below shows the size of a defconfig (+ xfs, squashfs, ftrace, kprobes) > kernel image on disk for base (before any changes applied), compile (with > changes, configured for compile-time page size) and boot (with changes, > configured for boot-time page size). >=20 > You can see the that compile-16k and 64k configs are actually slightly > smaller than the baselines; that's due to optimizing some buffer sizes > which didn't need to depend on page size during the series. The boot-time > image is ~1% bigger than the 64k compile-time image. I believe there is > scope to improve this to make it > equal to compile-64k if required: > | config | size/KB | diff/KB | diff/% | > | > |-------------|---------|---------|---------| > | > | base-4k | 54895 | 0 | 0.0% | > | base-16k | 55161 | 266 | 0.5% | > | base-64k | 56775 | 1880 | 3.4% | > | compile-4k | 54895 | 0 | 0.0% | > | compile-16k | 55097 | 202 | 0.4% | > | compile-64k | 56391 | 1496 | 2.7% | > | boot-4K | 57045 | 2150 | 3.9% | >=20 > And below shows the size of the image in memory at run-time, separated for > text and data costs. The boot image has ~1% text cost; most likely due to > the fact that PAGE_SIZE and friends are not compile-time constants so need > instructions to load the values and do arithmetic. I believe we could > eventually get the data cost to match the cost for the compile image for > the chosen page size by freeing > the ends of the static buffers not needed for the selected page size: > | | text | text | text | data | data | data= | > |=20 > | config | size/KB | diff/KB | diff/% | size/KB | diff/KB | diff/%= | > | > |-------------|---------|---------|---------|---------|---------|--------= =2D| > | > | base-4k | 20561 | 0 | 0.0% | 14314 | 0 | 0.0%= | > | base-16k | 20439 | -122 | -0.6% | 14625 | 311 | 2.2%= | > | base-64k | 20435 | -126 | -0.6% | 15673 | 1359 | 9.5%= | > | compile-4k | 20565 | 4 | 0.0% | 14315 | 1 | 0.0%= | > | compile-16k | 20443 | -118 | -0.6% | 14517 | 204 | 1.4%= | > | compile-64k | 20439 | -122 | -0.6% | 15134 | 820 | 5.7%= | > | boot-4K | 20811 | 250 | 1.2% | 15287 | 973 | 6.8%= | >=20 > Functional Testing > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > I've build-tested defconfig for all arches supported by tuxmake (which is > most) without issue. >=20 > I've boot-tested arm64 with CONFIG_ARM64_BOOT_TIME_PAGE_SIZE for all page > sizes and a few va-sizes, and additionally have run all the mm-selftests, > with no regressions observed vs the equivalent compile-time page size bui= ld > (although the mm-selftests have a few existing failures when run against > 16K and 64K kernels - those should really be investigated and fixed > independently). >=20 > Test coverage is lacking for many of the drivers that I've touched, but in > many cases, I'm hoping the changes are simple enough that review might > suffice? >=20 > Performance Testing > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > I've run some limited performance benchmarks: >=20 > First, a real-world benchmark that causes a lot of page table manipulation > (and therefore we would expect to see regression here if we are going to > see it anywhere); kernel compilation. It barely registers a change. Values > are times, > so smaller is better. All relative to base-4k: > | | kern | kern | user | user | real | real= | > |=20 > | config | mean | stdev | mean | stdev | mean | stdev= | > | > |-------------|---------|---------|---------|---------|---------|--------= =2D| > | > | base-4k | 0.0% | 1.1% | 0.0% | 0.3% | 0.0% | 0.3%= | > | compile-4k | -0.2% | 1.1% | -0.2% | 0.3% | -0.1% | 0.3%= | > | boot-4k | 0.1% | 1.0% | -0.3% | 0.2% | -0.2% | 0.2%= | >=20 > The Speedometer JavaScript benchmark also shows no change. Values are runs > per > min, so bigger is better. All relative to base-4k: > | config | mean | stdev | > | > |-------------|---------|---------| > | > | base-4k | 0.0% | 0.8% | > | compile-4k | 0.4% | 0.8% | > | boot-4k | 0.0% | 0.9% | >=20 > Finally, I've run some microbenchmarks known to stress page table > manipulations (originally from David Hildenbrand). The fork test > maps/allocs 1G of anon memory, then measures the cost of fork(). The munm= ap > test maps/allocs 1G of anon memory then measures the cost of munmap()ing > it. The fork test is known to be extremely sensitive to any changes that > cause instructions to be aligned differently in cachelines. When using th= is > test for other changes, I've seen double digit regressions for the > slightest thing, so 12% regression on this test is actually fairly good. > This likely represents the extreme worst case for regressions that will be > observed across other microbenchmarks (famous last > words). Values are times, so smaller is better. All relative to base-4k: > | | fork | fork | munmap | munmap | > |=20 > | config | mean | stdev | stdev | stdev | > | > |-------------|---------|---------|---------|---------| > | > | base-4k | 0.0% | 1.3% | 0.0% | 0.3% | > | compile-4k | 0.1% | 1.3% | -0.9% | 0.1% | > | boot-4k | 12.8% | 1.2% | 3.8% | 1.0% | >=20 > NOTE: The series applies on top of v6.11. >=20 > Thanks, > Ryan >=20 >=20 > Ryan Roberts (57): > mm: Add macros ahead of supporting boot-time page size selection > vmlinux: Align to PAGE_SIZE_MAX > mm/memcontrol: Fix seq_buf size to save memory when PAGE_SIZE is large > mm/page_alloc: Make page_frag_cache boot-time page size compatible > mm: Avoid split pmd ptl if pmd level is run-time folded > mm: Remove PAGE_SIZE compile-time constant assumption > fs: Introduce MAX_BUF_PER_PAGE_SIZE_MAX for array sizing > fs: Remove PAGE_SIZE compile-time constant assumption > fs/nfs: Remove PAGE_SIZE compile-time constant assumption > fs/ext4: Remove PAGE_SIZE compile-time constant assumption > fork: Permit boot-time THREAD_SIZE determination > cgroup: Remove PAGE_SIZE compile-time constant assumption > bpf: Remove PAGE_SIZE compile-time constant assumption > pm/hibernate: Remove PAGE_SIZE compile-time constant assumption > stackdepot: Remove PAGE_SIZE compile-time constant assumption > perf: Remove PAGE_SIZE compile-time constant assumption > kvm: Remove PAGE_SIZE compile-time constant assumption > trace: Remove PAGE_SIZE compile-time constant assumption > crash: Remove PAGE_SIZE compile-time constant assumption > crypto: Remove PAGE_SIZE compile-time constant assumption > sunrpc: Remove PAGE_SIZE compile-time constant assumption > sound: Remove PAGE_SIZE compile-time constant assumption > net: Remove PAGE_SIZE compile-time constant assumption > net: fec: Remove PAGE_SIZE compile-time constant assumption > net: marvell: Remove PAGE_SIZE compile-time constant assumption > net: hns3: Remove PAGE_SIZE compile-time constant assumption > net: e1000: Remove PAGE_SIZE compile-time constant assumption > net: igbvf: Remove PAGE_SIZE compile-time constant assumption > net: igb: Remove PAGE_SIZE compile-time constant assumption > drivers/base: Remove PAGE_SIZE compile-time constant assumption > edac: Remove PAGE_SIZE compile-time constant assumption > optee: Remove PAGE_SIZE compile-time constant assumption > random: Remove PAGE_SIZE compile-time constant assumption > sata_sil24: Remove PAGE_SIZE compile-time constant assumption > virtio: Remove PAGE_SIZE compile-time constant assumption > xen: Remove PAGE_SIZE compile-time constant assumption > arm64: Fix macros to work in C code in addition to the linker script > arm64: Track early pgtable allocation limit > arm64: Introduce macros required for boot-time page selection > arm64: Refactor early pgtable size calculation macros > arm64: Pass desired page size on command line > arm64: Divorce early init from PAGE_SIZE > arm64: Clean up simple cases of CONFIG_ARM64_*K_PAGES > arm64: Align sections to PAGE_SIZE_MAX > arm64: Rework trampoline rodata mapping > arm64: Generalize fixmap for boot-time page size > arm64: Statically allocate and align for worst-case page size > arm64: Convert switch to if for non-const comparison values > arm64: Convert BUILD_BUG_ON to VM_BUG_ON > arm64: Remove PAGE_SZ asm-offset > arm64: Introduce cpu features for page sizes > arm64: Remove PAGE_SIZE from assembly code > arm64: Runtime-fold pmd level > arm64: Support runtime folding in idmap_kpti_install_ng_mappings > arm64: TRAMP_VALIAS is no longer compile-time constant > arm64: Determine THREAD_SIZE at boot-time > arm64: Enable boot-time page size selection >=20 > arch/alpha/include/asm/page.h | 1 + > arch/arc/include/asm/page.h | 1 + > arch/arm/include/asm/page.h | 1 + > arch/arm64/Kconfig | 26 ++- > arch/arm64/include/asm/assembler.h | 78 ++++++- > arch/arm64/include/asm/cpufeature.h | 44 +++- > arch/arm64/include/asm/efi.h | 2 +- > arch/arm64/include/asm/fixmap.h | 28 ++- > arch/arm64/include/asm/kernel-pgtable.h | 150 +++++++++---- > arch/arm64/include/asm/kvm_arm.h | 21 +- > arch/arm64/include/asm/kvm_hyp.h | 11 + > arch/arm64/include/asm/kvm_pgtable.h | 6 +- > arch/arm64/include/asm/memory.h | 62 ++++-- > arch/arm64/include/asm/page-def.h | 3 +- > arch/arm64/include/asm/pgalloc.h | 16 +- > arch/arm64/include/asm/pgtable-geometry.h | 46 ++++ > arch/arm64/include/asm/pgtable-hwdef.h | 28 ++- > arch/arm64/include/asm/pgtable-prot.h | 2 +- > arch/arm64/include/asm/pgtable.h | 133 +++++++++--- > arch/arm64/include/asm/processor.h | 10 +- > arch/arm64/include/asm/sections.h | 1 + > arch/arm64/include/asm/smp.h | 1 + > arch/arm64/include/asm/sparsemem.h | 15 +- > arch/arm64/include/asm/sysreg.h | 54 +++-- > arch/arm64/include/asm/tlb.h | 3 + > arch/arm64/kernel/asm-offsets.c | 4 +- > arch/arm64/kernel/cpufeature.c | 93 ++++++-- > arch/arm64/kernel/efi.c | 2 +- > arch/arm64/kernel/entry.S | 60 +++++- > arch/arm64/kernel/head.S | 46 +++- > arch/arm64/kernel/hibernate-asm.S | 6 +- > arch/arm64/kernel/image-vars.h | 14 ++ > arch/arm64/kernel/image.h | 4 + > arch/arm64/kernel/pi/idreg-override.c | 68 +++++- > arch/arm64/kernel/pi/map_kernel.c | 165 ++++++++++---- > arch/arm64/kernel/pi/map_range.c | 201 ++++++++++++++++-- > arch/arm64/kernel/pi/pi.h | 63 +++++- > arch/arm64/kernel/relocate_kernel.S | 10 +- > arch/arm64/kernel/vdso-wrap.S | 4 +- > arch/arm64/kernel/vdso.c | 7 +- > arch/arm64/kernel/vdso/vdso.lds.S | 4 +- > arch/arm64/kernel/vdso32-wrap.S | 4 +- > arch/arm64/kernel/vdso32/vdso.lds.S | 4 +- > arch/arm64/kernel/vmlinux.lds.S | 48 +++-- > arch/arm64/kvm/arm.c | 10 + > arch/arm64/kvm/hyp/nvhe/Makefile | 1 + > arch/arm64/kvm/hyp/nvhe/host.S | 10 +- > arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 4 +- > arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c | 16 ++ > arch/arm64/kvm/mmu.c | 39 ++-- > arch/arm64/lib/clear_page.S | 7 +- > arch/arm64/lib/copy_page.S | 33 ++- > arch/arm64/lib/mte.S | 27 ++- > arch/arm64/mm/Makefile | 1 + > arch/arm64/mm/fixmap.c | 38 ++-- > arch/arm64/mm/hugetlbpage.c | 40 +--- > arch/arm64/mm/init.c | 26 +-- > arch/arm64/mm/kasan_init.c | 8 +- > arch/arm64/mm/mmu.c | 53 +++-- > arch/arm64/mm/pgd.c | 12 +- > arch/arm64/mm/pgtable-geometry.c | 24 +++ > arch/arm64/mm/proc.S | 128 ++++++++--- > arch/arm64/mm/ptdump.c | 3 +- > arch/arm64/tools/cpucaps | 3 + > arch/csky/include/asm/page.h | 3 + > arch/hexagon/include/asm/page.h | 2 + > arch/loongarch/include/asm/page.h | 2 + > arch/m68k/include/asm/page.h | 1 + > arch/microblaze/include/asm/page.h | 1 + > arch/mips/include/asm/page.h | 1 + > arch/nios2/include/asm/page.h | 2 + > arch/openrisc/include/asm/page.h | 1 + > arch/parisc/include/asm/page.h | 1 + > arch/powerpc/include/asm/page.h | 2 + > arch/riscv/include/asm/page.h | 1 + > arch/s390/include/asm/page.h | 1 + > arch/sh/include/asm/page.h | 1 + > arch/sparc/include/asm/page.h | 3 + > arch/um/include/asm/page.h | 2 + > arch/x86/include/asm/page_types.h | 2 + > arch/xtensa/include/asm/page.h | 1 + > crypto/lskcipher.c | 4 +- > drivers/ata/sata_sil24.c | 46 ++-- > drivers/base/node.c | 6 +- > drivers/base/topology.c | 32 +-- > drivers/block/virtio_blk.c | 2 +- > drivers/char/random.c | 4 +- > drivers/edac/edac_mc.h | 13 +- > drivers/firmware/efi/libstub/arm64.c | 3 +- > drivers/irqchip/irq-gic-v3-its.c | 2 +- > drivers/mtd/mtdswap.c | 4 +- > drivers/net/ethernet/freescale/fec.h | 3 +- > drivers/net/ethernet/freescale/fec_main.c | 5 +- > .../net/ethernet/hisilicon/hns3/hns3_enet.h | 4 +- > drivers/net/ethernet/intel/e1000/e1000_main.c | 6 +- > drivers/net/ethernet/intel/igb/igb.h | 25 +-- > drivers/net/ethernet/intel/igb/igb_main.c | 149 +++++++------ > drivers/net/ethernet/intel/igbvf/netdev.c | 6 +- > drivers/net/ethernet/marvell/mvneta.c | 9 +- > drivers/net/ethernet/marvell/sky2.h | 2 +- > drivers/tee/optee/call.c | 7 +- > drivers/tee/optee/smc_abi.c | 2 +- > drivers/virtio/virtio_balloon.c | 10 +- > drivers/xen/balloon.c | 11 +- > drivers/xen/biomerge.c | 12 +- > drivers/xen/privcmd.c | 2 +- > drivers/xen/xenbus/xenbus_client.c | 5 +- > drivers/xen/xlate_mmu.c | 6 +- > fs/binfmt_elf.c | 11 +- > fs/buffer.c | 2 +- > fs/coredump.c | 8 +- > fs/ext4/ext4.h | 36 ++-- > fs/ext4/move_extent.c | 2 +- > fs/ext4/readpage.c | 2 +- > fs/fat/dir.c | 4 +- > fs/fat/fatent.c | 4 +- > fs/nfs/nfs42proc.c | 2 +- > fs/nfs/nfs42xattr.c | 2 +- > fs/nfs/nfs4proc.c | 2 +- > include/asm-generic/pgtable-geometry.h | 71 +++++++ > include/asm-generic/vmlinux.lds.h | 38 ++-- > include/linux/buffer_head.h | 1 + > include/linux/cpumask.h | 5 + > include/linux/linkage.h | 4 +- > include/linux/mm.h | 17 +- > include/linux/mm_types.h | 15 +- > include/linux/mm_types_task.h | 2 +- > include/linux/mmzone.h | 3 +- > include/linux/netlink.h | 6 +- > include/linux/percpu-defs.h | 4 +- > include/linux/perf_event.h | 2 +- > include/linux/sched.h | 4 +- > include/linux/slab.h | 7 +- > include/linux/stackdepot.h | 6 +- > include/linux/sunrpc/svc.h | 8 +- > include/linux/sunrpc/svc_rdma.h | 4 +- > include/linux/sunrpc/svcsock.h | 2 +- > include/linux/swap.h | 17 +- > include/linux/swapops.h | 6 +- > include/linux/thread_info.h | 10 +- > include/xen/page.h | 2 + > init/main.c | 7 +- > kernel/bpf/core.c | 9 +- > kernel/bpf/ringbuf.c | 54 ++--- > kernel/cgroup/cgroup.c | 8 +- > kernel/crash_core.c | 2 +- > kernel/events/core.c | 2 +- > kernel/fork.c | 71 +++---- > kernel/power/power.h | 2 +- > kernel/power/snapshot.c | 2 +- > kernel/power/swap.c | 129 +++++++++-- > kernel/trace/fgraph.c | 2 +- > kernel/trace/trace.c | 2 +- > lib/stackdepot.c | 6 +- > mm/kasan/report.c | 3 +- > mm/memcontrol.c | 11 +- > mm/memory.c | 4 +- > mm/mmap.c | 2 +- > mm/page-writeback.c | 2 +- > mm/page_alloc.c | 31 +-- > mm/slub.c | 2 +- > mm/sparse.c | 2 +- > mm/swapfile.c | 2 +- > mm/vmalloc.c | 7 +- > net/9p/trans_virtio.c | 4 +- > net/core/hotdata.c | 4 +- > net/core/skbuff.c | 4 +- > net/core/sysctl_net_core.c | 2 +- > net/sunrpc/cache.c | 3 +- > net/unix/af_unix.c | 2 +- > sound/soc/soc-utils.c | 4 +- > virt/kvm/kvm_main.c | 2 +- > 172 files changed, 2185 insertions(+), 951 deletions(-) > create mode 100644 arch/arm64/include/asm/pgtable-geometry.h > create mode 100644 arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c > create mode 100644 arch/arm64/mm/pgtable-geometry.c > create mode 100644 include/asm-generic/pgtable-geometry.h >=20 > -- > 2.43.0 This is a generally very exciting patch set! I'm looking forward to seeing = it=20 land so I can take advantage of it for Fedora ARM and Fedora Asahi Remix. That said, I have a couple of questions: * Going forward, how would we handle drivers/modules that require a particu= lar=20 page size? For example, the Apple Silicon IOMMU driver code requires the=20 kernel to operate in 16k page size mode, and it would need to be disabled i= n=20 other page sizes. * How would we handle an invalid selection at boot? Can we program in a=20 fallback when the "wrong" mode is selected for a chip or something similar? Thanks again and best regards! (P.S.: Please add the asahi@ mailing list to the CC for future iterations o= f=20 this patch set and tag both Hector and myself in as well. Thanks!) =2D-=20 =E7=9C=9F=E5=AE=9F=E3=81=AF=E3=81=84=E3=81=A4=E3=82=82=E4=B8=80=E3=81=A4=EF= =BC=81/ Always, there's only one truth!