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 E1944EDA68D for ; Tue, 3 Mar 2026 16:09:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=m0eugKb8aGos3h+sBAkFolXk5OApfEJAp9DK80wSVAw=; b=d0afEY2pUnQ1Np1hzgSzaQNlCS jLE/I+7aD8DR6d/MBGWQsUaWX7p/YlrjVjelw0s7nvrOyxouIs1tu7RIwDmLoOFHZSYmiTRHPI85Q yfTK5yxqi+NHeu/pNwQSlABIIp6bydjUiwSdFo/HVeGUezjirO8QQbTWf9D8i2cmWvkaNbQTHArEA hyEfv7RUdpYlUYzHKBc221ho4fOLQchN6CnEUhrskj2ZXP67bPFoJenJG/V/QuKHR15r3KzWXY51L 12F/CpJzreKRVHEl+MHOxv+IaNSPF274W+XwX5x50mcRchsPADR6cRkaGZZXtQDYebAiR9gCm1o9+ gn5cwelw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSJE-0000000FWlR-18dV; Tue, 03 Mar 2026 16:09:20 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSJB-0000000FWkJ-1mcx; Tue, 03 Mar 2026 16:09:18 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id C608B68BFE; Tue, 3 Mar 2026 17:09:11 +0100 (CET) Date: Tue, 3 Mar 2026 17:09:11 +0100 From: Christoph Hellwig To: Eric Biggers Cc: Christoph Hellwig , Andrew Morton , Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: [PATCH 09/25] xor: move generic implementations out of asm-generic/xor.h Message-ID: <20260303160911.GI7021@lst.de> References: <20260226151106.144735-1-hch@lst.de> <20260226151106.144735-10-hch@lst.de> <20260228071521.GK65277@quark> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260228071521.GK65277@quark> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260303_080917_611087_B1EF52B7 X-CRM114-Status: GOOD ( 16.81 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Fri, Feb 27, 2026 at 11:15:21PM -0800, Eric Biggers wrote: > This makes the generic code always be included in xor.ko, even when the > architecture doesn't need it. For example, x86_64 doesn't need it, > since it always selects either the AVX or SSE code. True. OTOH it is tiny. > Have you considered putting the generic code in xor-core.c (or in > headers included by it) before xor_arch.h is included, and putting > __maybe_unused on the xor_block_template structs? Then they'll still be > available for arch_xor_init() to use, but any of them that aren't used > in a particular build will be optimized out as dead code by the > compiler. And earlier version did this, but it's a bit ugly. What I might consider is to require architectures that provide optimized version to opt into any generic one they want to use. This would require extra kconfig symbols, but be a lot cleaner overall.