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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4A9BC43334 for ; Tue, 28 Jun 2022 15:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346220AbiF1Psj (ORCPT ); Tue, 28 Jun 2022 11:48:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347960AbiF1Pr1 (ORCPT ); Tue, 28 Jun 2022 11:47:27 -0400 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3945937A03; Tue, 28 Jun 2022 08:47:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656431246; x=1687967246; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=ZsLTlpPVTkp+QEt+1Ek5ZOFyD2hxJXmK6Jry4VmCBfo=; b=CnUGHsjFBEmWBGGPiAolbfJEqSP+C6I+16ubdgOwmv06nOi5Yje0xh7r o5GnFyxnLx0A91HDRx46ol7inZeSg3bvO6dJACKDzoiH21Rwh5S6vE6iq gE5tiUotj8OoC2ncAKSJPVNsviaDbwFTDxu8dz1S7KbuHi1YPUwFC1xVc +uho9Q4V0P2vJNcCP5U0+LRZOeZA6Q77gkhCA7Lb/H3I3jg62KOI8hvcy IXR+llGsxh3IwJOf18JBdbb9YvL2j7EtNIuUHQ7I/faXyjfZZViG6Qd6A uSOsvAv9h4//aTDc1pbyTY2yV2q++wuNPlgBXCzfM1632IYanPotUYhpV A==; X-IronPort-AV: E=McAfee;i="6400,9594,10392"; a="264817913" X-IronPort-AV: E=Sophos;i="5.92,229,1650956400"; d="scan'208";a="264817913" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2022 08:47:18 -0700 X-IronPort-AV: E=Sophos;i="5.92,229,1650956400"; d="scan'208";a="587910883" Received: from staibmic-mobl1.amr.corp.intel.com (HELO [10.209.67.166]) ([10.209.67.166]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2022 08:47:18 -0700 Message-ID: <086370dd-281f-5ac6-3a0f-f1b80500c668@intel.com> Date: Tue, 28 Jun 2022 08:46:14 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v5 0/6] Add hardware prefetch control driver for A64FX and x86 Content-Language: en-US To: Linus Walleij , "tarumizu.kohei@fujitsu.com" Cc: Greg KH , "catalin.marinas@arm.com" , "will@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "rafael@kernel.org" , "lenb@kernel.org" , "mchehab+huawei@kernel.org" , "eugenis@google.com" , "tony.luck@intel.com" , "pcc@google.com" , "peterz@infradead.org" , "marcos@orca.pet" , "marcan@marcan.st" , "nicolas.ferre@microchip.com" , "conor.dooley@microchip.com" , "arnd@arndb.de" , "ast@kernel.org" , "peter.chen@kernel.org" , "kuba@kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-acpi@vger.kernel.org" References: <20220607120530.2447112-1-tarumizu.kohei@fujitsu.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/27/22 02:36, Linus Walleij wrote: > The right way to solve this is to make the Linux kernel contain the > necessary heuristics to identify which tasks and thus cores need this > to improve efficiency and then apply it automatically. I agree in theory. But, I also want a pony in theory. Any suggestions for how to do this in the real world? Otherwise, I'm inclined to say that this series incrementally makes things better in the real world by at least moving folks away from wrmsr(1).