From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A3A0FC88E53 for ; Tue, 15 Sep 2026 12:24:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=plyYlqXE9r/eLLyWL5Af2MMLW3S17NuqbFTt+/evbfg=; b=OQffiMvpqUg/Vd 4/NdiMUxlDa9S7yR1sux+p469bZkDjVB81xfBcINMscLB+i1kNCKN1rWzjhmBSUN1voo8qbm8lSuj lF4AoFEy1rrH0s5O2Y8PP3S2lYicUVO+dOAGrJt8j5kz4O5V8quRslUXa7GF7eh74XboCmx+qbQel ZDQc1MzjLf/iWxqmrdF52XCIAllQmMVpU/SM72i9zs1hdQYAvXgLp1QRYa1gCFtz7RGFbaQcZUie6 J1yy+EQ+8BVKZ0llRn9TjxWkZwMB2kwLyNhK7etTRty73vQSSBaZRU8XgRsv9oheC8XxpTpSE4CKV WnSG0cXRDIxpsFdVA09A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6SD9-00000006TwN-1rjh; Tue, 15 Sep 2026 12:24:31 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6SD7-00000006Tvg-2ysE; Tue, 15 Sep 2026 12:24:29 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id D66EF602A8; Tue, 15 Sep 2026 12:24:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 965111F00893; Tue, 15 Sep 2026 12:24:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789475068; bh=oybH7eUIXKQPekIV7WrspdJ7cyHg8nnBvzsloGcaUcE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VSaS7F8OJuNuEs3hoUYH76UztTiKslXOl7yAzD2g4gLjW+wKdODE4ANHrYphBLvcC dGQy3ey9t5efNqzisI0bUxDeGSY5PMDK/ax9/0NQvgRzWjcV7F7EvSP2B/s6DK3yVq LFk4eZeHY6yXs4Bdceq1zyCgKeMUHsFp59hbk5m8WeQ+Fb5DlCQHi/TGx8gXJTsZ5g 4PAd+0aC9GXETgFVdHQurW/S48n9SVPZKOb37fkbk6zWKNxSbX4MCdrWfrI+5lw5mV ic86w///f180dvzmes95xRX+VFp+twm4uFnIt2UCdpXtQU6L7BYsK4DvAH5U2Nt83Z YRdnbbuTH1zuw== Date: Tue, 15 Sep 2026 13:24:17 +0100 From: "Lorenzo Stoakes (ARM)" To: Linus Torvalds Cc: Josh Poimboeuf , 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 , 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 , Kees Cook , "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@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 , linux-hardening@vger.kernel.org Subject: Re: [PATCH v2 15/21] objtool: cache relocations, do less work Message-ID: References: <20260914-build-speedup-v2-0-39817ec5db23@kernel.org> <20260914-build-speedup-v2-15-39817ec5db23@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Sep 14, 2026 at 03:30:19PM -0700, Linus Torvalds wrote: > On Mon, 14 Sept 2026 at 15:23, Josh Poimboeuf wrote: > > > > There might be more efficient ways to structure the considerable amount > > of data, like replacing "struct instruction" with "struct basic_block" > > or so, but it's hard to know whether that would be a net positive. > > Yeah, I was thinking that you'd only hash instructions as you find > them if they are obvious "I need this instruction", and then try to > hash them *again* if they are branch targets (and just have a "already > hashed" flag). > > That way random number instructions would not be on the hash - unless > they become branch targets. > > And you wouldn't ever really have to track any complicated decisions > (like that whole "basic block" thing - I agree that it's painful, > because the shape of a basic block will change over time as you find > branch targets). > > But not a big deal. More an idle thought brought on by that other > patch that changed the hash table size, and this discussion that was > talking about the hashing - or not hashing - of sections. > > So more of a "if it is easy and straightforward" kind of thing. Obviously I defer to Josh on this, but it seems from what he said it's probably a little involved and maybe tricky to figure out how much impact it might have. Anyway v3 drops the relocation hash altogether so 1 out of 2 ain't bad ;) > > Linus -- Cheers, Lorenzo _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv