From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 A2686360; Mon, 22 Jan 2024 00:16:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705882601; cv=none; b=sB974ZVv8DWA2lmjG6/olf7kBvawOBKn/YogUa7fly02byJj6IOTFVWWK+5TGeRWxV0uZD1oiiooemIT0uxhUybrd3GqaNxRcP2GzQUrhdwx1ymDPr0oKqXV2nvocjcyWzmML07pXAPhLtGbJYN/DqQ+zix6Wg6WSoZDmxyJ0NA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705882601; c=relaxed/simple; bh=TdIhc3Udceb38wI9THCR6IdLlWdrOaBwsuVbGu+VNjw=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=GQ0bYzfwiAxp+GpG1KsMxWEDQ2L6jZ2CMXwBB1a/yJQFA5MMwXqSCmfgYSBWhjQVddpMqDIj1ECOW0K8NtEn2bulPgDDjck3zLc0BQ7cxyEcQS45xu4fico+AziLEvFEfV9uEC2py/CTGEqaAKTNE+LG7tuOYthngFRgCqVT6b4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=F1Q01wyx; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="F1Q01wyx" Received: from [IPv6:::1] ([172.59.160.46]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 40M0G7Gt2251320 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Sun, 21 Jan 2024 16:16:10 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 40M0G7Gt2251320 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024011201; t=1705882571; bh=TdIhc3Udceb38wI9THCR6IdLlWdrOaBwsuVbGu+VNjw=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=F1Q01wyxJe1GAeuSbw/qbXOt4C/TGQ1daCC8OU8t0SktRft7MpHW3Hcq5XlfHIXeH xtAiNwMsFF8fzoLQOMKqyxNKNiFk0yUaO59m8qYlB29OuksaIRPuCneGhduDVQdO48 BKhQYxifzpoJtwYQK3eHXKTKcjiIjgjDMSJOuGtDRY/KgjQeurXQEnYZxDjM6eYsRX W+MxPl5MfAuv0MEkctdwvI7dgHV7zUu8F9oNj9/2S8lpWZuTduq0Eth/VgCZovEVdR vO+r6SZheacAwxFHoeOqDZs2JNBjb78MqA0D/tYQ2+D6jma3aVmZj+gayzJUa5o4sQ 5EQ/M6caxQe4g== Date: Sun, 21 Jan 2024 16:15:57 -0800 From: "H. Peter Anvin" To: Thorsten Glaser CC: Peter Zijlstra , x86@kernel.org, rostedt@goodmis.org, torvalds@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org, jpoimboe@redhat.com, alexei.starovoitov@gmail.com, mhiramat@kernel.org Subject: Re: [PATCH 1/2] x86: Remove dynamic NOP selection User-Agent: K-9 Mail for Android In-Reply-To: References: <20210312113253.305040674@infradead.org> <20210312115749.065275711@infradead.org> Message-ID: <20B57BDC-9A3F-4B02-9BA9-41477088A6CE@zytor.com> Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On January 21, 2024 3:58:11 PM PST, Thorsten Glaser wrote= : >H=2E Peter Anvin dixit: > >> But yes, with all even remotely recent CPUs all actually handling nopl >> properly, this isn't relevant anymore=2E > >This was, incidentally, triggered by looking into a problem report that >something did *not* work on a Geode LX system=2E > >People don=E2=80=99t just run Linux on =E2=80=9Crecent CPUs=E2=80=9D (tho= ugh I at least got me >an Atom and a Core2Duo for it and run BSD on my Pentium-M and VIA C7 >systems)=2E > >bye, >//mirabilos Yes, but it is a matter of where we optimize for performance as opposed to= correctness=2E