From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB1A21DF988 for ; Sat, 26 Apr 2025 19:09:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745694596; cv=none; b=SHulNxdY8jqxDDa/O69kYXReWVU6SKN4j+CtNXgdj50yc/ntmqUwG3JnDr6qUyIVZdyaaMxZrFW+E0wytnae5nr3saTTgS5NLn5N6Kf4VUJPtpxdM80IpvpjwyOvU3M557eo5chzQMWlTKE7LoGD1kAOHQRfyrI6iUEyYZ9N6Ac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745694596; c=relaxed/simple; bh=07l3WctL9NqhfdN89XZmqkm5zTdk90Q/ztrcy/DErjg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nZXDNKIV60bIKEDwhhgopzrihmmrVpNoaCCq7tAa94kYZI2W5WvpXJpzUBI2pGwUm2DGEi0kM0mhmSYuPUZz02YRj4hmiheeFL+IFLBuPcvotx/Xzs3QHMBu++qdLwDAP/SlrAa7ujYwVjhfEISx2MKA+fniBvcB2ZenrAQ/RwI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NVfY67VW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NVfY67VW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92973C4CEE2; Sat, 26 Apr 2025 19:09:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745694596; bh=07l3WctL9NqhfdN89XZmqkm5zTdk90Q/ztrcy/DErjg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NVfY67VWhCVqlpe7m2m9BJZW2pOZWxvq9m7gF6cpOJC+vZijOXds7YNWbZ8+8wBvK v0gjXTJEl6up/BuqExzotOfQNrcXc/iSM12njyAUxBde+8Eggt3fT+zKp8fTm6tuJg PqZcKEa/R/OEzNXAO+yXnU6NhDVPIpDthVGKhEvfVRk+4pGzH/5SzmMqyuTgw06Net 2QKbaK8Jk0J2yQtumpT3m2LmZs6und/oVXYc2A3uUnU4wd5IXdmNpOFcvbYSDKcFti t0C5fSSHVbnxYk09jk/DjG8CzVR9FPjIaAhbJGXXFKVxVxysfDBpTOKlMWy2bDoXHd +ZfFc3/gEW3qQ== Date: Sat, 26 Apr 2025 21:09:50 +0200 From: Ingo Molnar To: Arnd Bergmann Cc: Arnd Bergmann , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Juergen Gross , Boris Ostrovsky , Alexander Usyskin , Greg Kroah-Hartman , Mateusz =?utf-8?Q?Jo=C5=84czyk?= , Mike Rapoport , Ard Biesheuvel , Peter Zijlstra , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Linus Torvalds Subject: Re: [PATCH] [RFC] x86/cpu: rework instruction set selection Message-ID: References: <20250425141740.734030-1-arnd@kernel.org> 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-Disposition: inline In-Reply-To: * Arnd Bergmann wrote: > CMOV is missing not just on old Socket 5/7 CPUs (Pentium MMX, AMD K6, > Cyrix MII) but also newer embedded Via C3, Geode GX and > Vortex86DX/MX/EX/DX2. The replacement Nehemiah (2003), GeodeLX (2005) > and Vortex86DX3/EX2 (2015!) have CMOV, but the old ones were sold > alongside them for years, and some of the 586-class Vortex86 products > are still commercially available. Very few (if any) of the commercially available products will run modern 6.16+ kernels, right? Note that the real danger the 32-bit x86 kernel is going to be facing in 2-5 years is total removal due to lack of development interest, but I think we can support 686+ reasonably far into the future, and can keep it tested reasonably - while covering like 99%+ of the currently available 32-bit-only x86 products on the market. The fewer variants, the better. Thanks, Ingo