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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49e6576122bsm80821885e9.2.2026.09.11.10.33.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2026 10:33:34 -0700 (PDT) Date: Fri, 11 Sep 2026 18:33:33 +0100 From: David Laight To: Nicolas Schier Cc: Nathan Chancellor , "Lorenzo Stoakes (ARM)" , Linus Torvalds , 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?B?QmrDtnJu?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?UTF-8?B?w5Z6a2Fu?= , Jonathan Corbet , Randy Dunlap , 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 Subject: Re: [PATCH 12/23] kbuild: avoid re-running compiler and linker probes Message-ID: <20260911183333.1df0f2e2@pumpkin> In-Reply-To: <20260910-translucent-sweet-sidewinder-7acacb@l-nschier-aarch64> References: <20260908-build-speedup-v1-0-5dc1ac01672d@kernel.org> <20260908-build-speedup-v1-12-5dc1ac01672d@kernel.org> <178901395292.3971858.13236774094648272066.b4-review@b4> <20260910-translucent-sweet-sidewinder-7acacb@l-nschier-aarch64> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 10 Sep 2026 17:42:35 +0200 Nicolas Schier wrote: ... > Yes, skimming through the patch, I thought about that, too. Moving more > cc option checks to Kconfig will make building out-of-tree kmods with a > different compiler more dangerous. Maybe we will have to make the > warning in Makefile's prepare (external kmods) target a bit louder. One problem is that distributions have a nasty habit of shipping kernels that are compiled with a different compiler version to they actually ship as a compiler. In some cases the versions are clearly the same - but the version strings differ. David