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[144.49.247.116]) by smtp-relay.gmail.com with ESMTPS id 71dfb90a1353d-5c7ebf6adbdsm8539275e0c.0.2026.09.09.14.59.11 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Sep 2026 14:59:12 -0700 (PDT) X-Relaying-Domain: broadcom.com X-CFilter-Loop: Reflected Received: by mail-qt1-f200.google.com with SMTP id d75a77b69052e-53094ff7090so57212701cf.1 for ; Wed, 09 Sep 2026 14:59:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1788991151; x=1789595951; darn=lists.linux.dev; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=qHHcpy5QeLt7Tn0UZNn69+aN/4XUzCy9zf9R/ItNdpQ=; b=eDKKEKPAIPAuWTvJbOB7a0DKuc7xFxo5zZGaQ/5ntNbcVmkHPABzFXYLogbsjmhtXP D/jhMkgFdMymKVpu4ooKdVfSrJsSiKj6Y0rYmUdRQxYUsJzo44k34SrfqhHXIqNKHPpC VJU7+bwN6kcGN0yqfHz9Ij+qmsCXurpr0fWdM= X-Forwarded-Encrypted: i=1; AKwUvBwMXNNAvsbVEeUDbNp0b4WnfChnukn3YgXWjD3q5y2dfYxxhkxD1U6qm2aEAFGlflKgix0v@lists.linux.dev X-Received: by 2002:a05:622a:2592:b0:530:3554:6482 with SMTP id d75a77b69052e-530548511c0mr498367731cf.18.1788991151310; Wed, 09 Sep 2026 14:59:11 -0700 (PDT) X-Received: by 2002:a05:622a:2592:b0:530:3554:6482 with SMTP id d75a77b69052e-530548511c0mr498367041cf.18.1788991150882; Wed, 09 Sep 2026 14:59:10 -0700 (PDT) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-53054180b0asm150783051cf.19.2026.09.09.14.59.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Sep 2026 14:59:10 -0700 (PDT) Message-ID: Date: Wed, 9 Sep 2026 14:58:59 -0700 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 00/23] kbuild: significantly speed up kernel builds To: "Lorenzo Stoakes (ARM)" , Linus Torvalds , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Masahiro Yamada , Alexey Gladkov , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Arnd Bergmann , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Ilias Apalodimas , Josh Poimboeuf , Peter Zijlstra , Miguel Ojeda , Boqun Feng , Gary Guo , =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?UTF-8?Q?Onur_=C3=96zkan?= , Jonathan Corbet , Randy Dunlap Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Jens Axboe References: <20260908-build-speedup-v1-0-5dc1ac01672d@kernel.org> Content-Language: en-US, fr-FR From: Florian Fainelli Autocrypt: addr=florian.fainelli@broadcom.com; keydata= xsBNBFPAG8ABCAC3EO02urEwipgbUNJ1r6oI2Vr/+uE389lSEShN2PmL3MVnzhViSAtrYxeT M0Txqn1tOWoIc4QUl6Ggqf5KP6FoRkCrgMMTnUAINsINYXK+3OLe7HjP10h2jDRX4Ajs4Ghs JrZOBru6rH0YrgAhr6O5gG7NE1jhly+EsOa2MpwOiXO4DE/YKZGuVe6Bh87WqmILs9KvnNrQ PcycQnYKTVpqE95d4M824M5cuRB6D1GrYovCsjA9uxo22kPdOoQRAu5gBBn3AdtALFyQj9DQ KQuc39/i/Kt6XLZ/RsBc6qLs+p+JnEuPJngTSfWvzGjpx0nkwCMi4yBb+xk7Hki4kEslABEB AAHNMEZsb3JpYW4gRmFpbmVsbGkgPGZsb3JpYW4uZmFpbmVsbGlAYnJvYWRjb20uY29tPsLB IQQQAQgAywUCZWl41AUJI+Jo+hcKAAG/SMv+fS3xUQWa0NryPuoRGjsA3SAUAAAAAAAWAAFr ZXktdXNhZ2UtbWFza0BwZ3AuY29tjDAUgAAAAAAgAAdwcmVmZXJyZWQtZW1haWwtZW5jb2Rp bmdAcGdwLmNvbXBncG1pbWUICwkIBwMCAQoFF4AAAAAZGGxkYXA6Ly9rZXlzLmJyb2FkY29t Lm5ldAUbAwAAAAMWAgEFHgEAAAAEFQgJChYhBNXZKpfnkVze1+R8aIExtcQpvGagAAoJEIEx tcQpvGagWPEH/2l0DNr9QkTwJUxOoP9wgHfmVhqc0ZlDsBFv91I3BbhGKI5UATbipKNqG13Z TsBrJHcrnCqnTRS+8n9/myOF0ng2A4YT0EJnayzHugXm+hrkO5O9UEPJ8a+0553VqyoFhHqA zjxj8fUu1px5cbb4R9G4UAySqyeLLeqnYLCKb4+GklGSBGsLMYvLmIDNYlkhMdnnzsSUAS61 WJYW6jjnzMwuKJ0ZHv7xZvSHyhIsFRiYiEs44kiYjbUUMcXor/uLEuTIazGrE3MahuGdjpT2 IOjoMiTsbMc0yfhHp6G/2E769oDXMVxCCbMVpA+LUtVIQEA+8Zr6mX0Yk4nDS7OiBlvOwE0E U8AbwQEIAKxr71oqe+0+MYCc7WafWEcpQHFUwvYLcdBoOnmJPxDwDRpvU5LhqSPvk/yJdh9k 4xUDQu3rm1qIW2I9Puk5n/Jz/lZsqGw8T13DKyu8eMcvaA/irm9lX9El27DPHy/0qsxmxVmU pu9y9S+BmaMb2CM9IuyxMWEl9ruWFS2jAWh/R8CrdnL6+zLk60R7XGzmSJqF09vYNlJ6Bdbs MWDXkYWWP5Ub1ZJGNJQ4qT7g8IN0qXxzLQsmz6tbgLMEHYBGx80bBF8AkdThd6SLhreCN7Uh IR/5NXGqotAZao2xlDpJLuOMQtoH9WVNuuxQQZHVd8if+yp6yRJ5DAmIUt5CCPcAEQEAAcLB gQQYAQIBKwUCU8AbwgUbDAAAAMBdIAQZAQgABgUCU8AbwQAKCRCTYAaomC8PVQ0VCACWk3n+ obFABEp5Rg6Qvspi9kWXcwCcfZV41OIYWhXMoc57ssjCand5noZi8bKg0bxw4qsg+9cNgZ3P N/DFWcNKcAT3Z2/4fTnJqdJS//YcEhlr8uGs+ZWFcqAPbteFCM4dGDRruo69IrHfyyQGx16s CcFlrN8vD066RKevFepb/ml7eYEdN5SRALyEdQMKeCSf3mectdoECEqdF/MWpfWIYQ1hEfdm C2Kztm+h3Nkt9ZQLqc3wsPJZmbD9T0c9Rphfypgw/SfTf2/CHoYVkKqwUIzI59itl5Lze+R5 wDByhWHx2Ud2R7SudmT9XK1e0x7W7a5z11Q6vrzuED5nQvkhAAoJEIExtcQpvGagugcIAJd5 EYe6KM6Y6RvI6TvHp+QgbU5dxvjqSiSvam0Ms3QrLidCtantcGT2Wz/2PlbZqkoJxMQc40rb fXa4xQSvJYj0GWpadrDJUvUu3LEsunDCxdWrmbmwGRKqZraV2oG7YEddmDqOe0Xm/NxeSobc MIlnaE6V0U8f5zNHB7Y46yJjjYT/Ds1TJo3pvwevDWPvv6rdBeV07D9s43frUS6xYd1uFxHC 7dZYWJjZmyUf5evr1W1gCgwLXG0PEi9n3qmz1lelQ8lSocmvxBKtMbX/OKhAfuP/iIwnTsww 95A2SaPiQZA51NywV8OFgsN0ITl2PlZ4Tp9hHERDe6nQCsNI/Us= In-Reply-To: <20260908-build-speedup-v1-0-5dc1ac01672d@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e On 9/8/26 13:55, Lorenzo Stoakes (ARM) wrote: > A typical kernel build consists of a frustratingly large amount of time > spent stuck in single-threaded bottlenecks. > > It turns out that there's a lot we can do about this and doing so > significantly impacts kernel build times. > > This series makes allmodconfig builds up to 36% faster, incremental builds > up to ~70% faster, and noop builds up to ~90% faster. > > Builds are faster across the board on every device I tested. > > Machines used for perf testing: > > * Threadripper - x86, AMD Threadripper 9980X, 64 cores, 128 threads > * EPYC - x86, 2 socket EPYC 9754, 256 cores, 512 threads > * M2 - arm64, 2022 M2 macbook pro, 8 cores, 8 threads > (4 perf, 4 efficiency) My AMD EPYC 9454P server shows an improvement in the order of 13% using the arm64's defconfig and make -j97. Thanks for doing this! -- Florian