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Tue, 15 Sep 2026 04:54:22 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: AGrkui6Nx9zw Date: Tue, 15 Sep 2026 10:53:51 +0200 From: "Arnd Bergmann" To: "Linus Torvalds" , "Kees Cook" Cc: "Lorenzo Stoakes" , "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" , "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" , "Gustavo A. R. Silva" , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-riscv@lists.infradead.org, Linux-Arch , linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, "Jens Axboe" , linux-hardening@vger.kernel.org Message-Id: <7646eb0c-7c4a-4ec2-9562-66a74c4d9858@app.fastmail.com> In-Reply-To: References: <20260914-build-speedup-v2-0-39817ec5db23@kernel.org> <202609140833.88C0E16E50@keescook> Subject: Re: [PATCH v2 00/21] kbuild: significantly speed up kernel builds Content-Type: text/plain Content-Transfer-Encoding: 7bit On Mon, Sep 14, 2026, at 17:53, Linus Torvalds wrote: > On Mon, 14 Sept 2026 at 08:41, Kees Cook wrote: >> >> One area I think might solved via an LLM is the 3-pass kallsyms stuff. >> If we could get a deterministic kallsyms build in 1 pass, that would be >> very nice. A lot of people have tried, but it has eluded upstreaming. > > Even the three-pass one hasn't apparently always been entirely > deterministic. We've had random reports over the years of it failing > in some circumstances. This tends to break whenever a linker (rather than the compiler) starts creating a new type of symbols that show up in pass 2. > Maybe we've fixed it all, or maybe the failures just go imperceptibly > rare. Regardless, it has definitely been fragile. The rate seems to be once every few years, looking at the list of exceptions added to scripts/kallsyms.c (now scripts/mksysmap): efe6e3068067 ("kallsyms: fix nonconverging kallsyms table with lld") 516d980f8541 ("scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.*") b9b74be163a2 ("ARM: 8555/1: kallsyms: ignore ARM mode switching veneers") I'm sure there are other instances on architectures that get less build coverage. Arnd