From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.avm.de (mail.avm.de [212.42.244.119]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C61094AE129 for ; Fri, 11 Sep 2026 18:18:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.42.244.119 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789150690; cv=none; b=EA7RgNC+AjdQsPWwt9MUer6z7ZrrheDqigQse7jgB+HeHVXhYuj5evg8/xGqay2DgRZHdn5Z2qkdCDbeUqe3vTSuIfjZ2Q0gw/qGRnI5JSTHb7XKWR92lI6FAZYI1s/w7Xz1zK16FlrleKImtvhfhtN3GYbL4lCHfDkjm9g2tQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789150690; c=relaxed/simple; bh=4m5yk/k55asBFxV3Yrw4jckjF0Ccpy/QWIGf4quzAAg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kWuWdCdfrQBBZGIL0fmRDNH+woyxIOAVreKHctvXOxdAqqJTJkfo6eYYC4kSLT3fSdlceycBQlGFodUCP67DB9veiT/dVnKxocM1qkAeZQcABO0OF8Q9vHmaF62C//wuRG5pkTM8NsB+6aX62rWf5R7z9FQUDYVO/Tm9/kKThh0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=fritz.com; spf=pass smtp.mailfrom=fritz.com; dkim=pass (2048-bit key) header.d=fritz.com header.i=@fritz.com header.b=JaZtIxDc; arc=none smtp.client-ip=212.42.244.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=fritz.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fritz.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fritz.com header.i=@fritz.com header.b="JaZtIxDc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=fritz.com; s=mail; t=1789150679; bh=4m5yk/k55asBFxV3Yrw4jckjF0Ccpy/QWIGf4quzAAg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JaZtIxDcGsAhl6feYgMTLPhM4TvDUZ2sl3JNnH2JFFoQdzmzW4q6bYRMnxUPMjnEc r5CRGWNo8fX1u5krGSYO1u20i2Rk9mrBDRciL6ux+I8uxtJyLBrvtCbCXkOp2aA2LJ iRRwBeZ+V4GelVSlECpcmHXPfSIPnuBLQ2CTc5nxplgYgl7ItDrvtw6vx9pvRTbSgP fDxFO0bxG9fuFw7fFmQlDSayWEmJYoWOOoli4hw4RTJCupy+d3/Zia+U429/y8q0lt P/HDIqEGutH0Z6nauMm328pxcWKPKCoWw382mLEq4cIzOXDmQSAIXGmwP/2Iez6AdJ OzEFeLaY5K1uA== Received: from [2001:bf0:244:244::78] (helo=mail.avm.de) by mail.avm.de with ESMTP (eXpurgate 4.57.1) (envelope-from ) id 6aa445d6-ea3f-7f0000032729-7f000001e59e-1 for ; Fri, 11 Sep 2026 20:17:58 +0200 Received: from mail-auth.fritz.com (unknown [IPv6:2001:bf0:244:244::78]) by mail.avm.de (Postfix) with ESMTPS; Fri, 11 Sep 2026 20:17:58 +0200 (CEST) Date: Fri, 11 Sep 2026 20:17:57 +0200 From: Nicolas Schier To: David Laight 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: <20260911-invaluable-indigo-seal-e31aec@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> <20260911183333.1df0f2e2@pumpkin> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260911183333.1df0f2e2@pumpkin> Organization: FRITZ! Technology GmbH x-ms-reactions: disallow X-purgate-ID: 149429::1789150678-02CFD720-8112F834/0/0 X-purgate-type: clean X-purgate-size: 775 X-purgate: This mail is considered clean (visit https://www.eleven.de for further information) X-purgate: clean X-pfmilter: host: postfix-mx-02 mail-id: 02F82A0215 external: no On Fri, Sep 11, 2026 at 06:33:33PM +0100, David Laight wrote: > 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. yeah, I guess you hit the mark. -- Nicolas