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 6D156C433F5 for ; Sun, 2 Oct 2022 21:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229656AbiJBV4L (ORCPT ); Sun, 2 Oct 2022 17:56:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229551AbiJBV4I (ORCPT ); Sun, 2 Oct 2022 17:56:08 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 443F925EAF for ; Sun, 2 Oct 2022 14:56:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664747767; x=1696283767; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=MHXZOslfCcDE9hrF1V4VyXXTWYMqdv0k/V1937kqx5s=; b=W4zeYSzFWNumjCJgO+TjlHHu1bbGRweL4hOPNejN4U8qqlFPPlLdYimK tjafxTROWh95j0DR1SIqeRoPyWDi3ilN7xXhgsxF2jGm0UyyTcCBZ+F85 ldQDAX53jlbPq4rt/EyY3oeRGN0bJyqXVuaNlhvN95Ukp12S6bfaAJ6VY cIWhkpk8hMn7XLGHSdbNxnkIz+R/36bY6VrwHNjSxEeLYgsRTJgQMRKDl qEIR2kyJNBqXcCSvmY2rg87Eqe8tDICLPKPE3G6U9lqkHcu8PmnZw1fJh FK9thv3SylIXuVousuhZqYwV93WUpoAgNJMsEoZf5nkdgnqo9Bx1100lJ Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10488"; a="300114512" X-IronPort-AV: E=Sophos;i="5.93,363,1654585200"; d="scan'208";a="300114512" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Oct 2022 14:56:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10488"; a="574433653" X-IronPort-AV: E=Sophos;i="5.93,363,1654585200"; d="scan'208";a="574433653" Received: from ranerica-svr.sc.intel.com ([172.25.110.23]) by orsmga003.jf.intel.com with ESMTP; 02 Oct 2022 14:56:06 -0700 Date: Sun, 2 Oct 2022 15:02:29 -0700 From: Ricardo Neri To: Peter Zijlstra Cc: Juri Lelli , Vincent Guittot , Ricardo Neri , "Ravi V. Shankar" , Ben Segall , Daniel Bristot de Oliveira , Dietmar Eggemann , Len Brown , Mel Gorman , "Rafael J. Wysocki" , Srinivas Pandruvada , Steven Rostedt , Tim Chen , Valentin Schneider , x86@kernel.org, linux-kernel@vger.kernel.org, "Tim C . Chen" Subject: Re: [RFC PATCH 23/23] x86/process: Reset hardware history in context switch Message-ID: <20221002220229.GA17545@ranerica-svr.sc.intel.com> References: <20220909231205.14009-1-ricardo.neri-calderon@linux.intel.com> <20220909231205.14009-24-ricardo.neri-calderon@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 27, 2022 at 02:53:29PM +0200, Peter Zijlstra wrote: > On Fri, Sep 09, 2022 at 04:12:05PM -0700, Ricardo Neri wrote: > > Reset the classification history of the current task when switching to > > the next task. Hardware will start anew the classification of the next > > running task. > > Please quantify the cost of this HRESET instruction. Sure Peter. I will. Thanks and BR, Ricardo