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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85777C43144 for ; Tue, 26 Jun 2018 23:40:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1331022544 for ; Tue, 26 Jun 2018 23:40:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1331022544 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933909AbeFZXka (ORCPT ); Tue, 26 Jun 2018 19:40:30 -0400 Received: from mga05.intel.com ([192.55.52.43]:25310 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752332AbeFZXk2 (ORCPT ); Tue, 26 Jun 2018 19:40:28 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2018 16:40:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,276,1526367600"; d="scan'208";a="240918025" Received: from spandruv-desk.jf.intel.com ([10.54.75.31]) by fmsmga006.fm.intel.com with ESMTP; 26 Jun 2018 16:40:27 -0700 Message-ID: Subject: Re: [PATCH] Documentation: intel_pstate: Describe hwp_dynamic_boost sysfs knob From: Srinivas Pandruvada To: "Rafael J. Wysocki" , Linux PM Cc: Linux Documentation , Jonathan Corbet , LKML Date: Tue, 26 Jun 2018 16:40:27 -0700 In-Reply-To: <306013127.TOMvMKusHN@aspire.rjw.lan> References: <306013127.TOMvMKusHN@aspire.rjw.lan> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.2 (3.28.2-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-06-26 at 17:20 +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Document the recently introduced hwp_dynamic_boost sysfs knob > allowing user space to tell intel_pstate to use iowait boosting > in the active mode with HWP enabled (to improve performance). > > Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada > --- > Documentation/admin-guide/pm/intel_pstate.rst | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > Index: linux-pm/Documentation/admin-guide/pm/intel_pstate.rst > =================================================================== > --- linux-pm.orig/Documentation/admin-guide/pm/intel_pstate.rst > +++ linux-pm/Documentation/admin-guide/pm/intel_pstate.rst > @@ -378,6 +378,17 @@ argument is passed to the kernel in the > but it affects the maximum possible value of per-policy P- > state limits > (see `Interpretation of Policy Attributes`_ below for > details). > > +``hwp_dynamic_boost`` > + This attribute is only present if ``intel_pstate`` works in > the > + `active mode with the HWP feature enabled HWP_>`_ in > + the processor. If set (equal to 1), it causes the minimum > P-state limit > + to be increased dynamically for a short time whenever a task > previously > + waiting on I/O is selected to run on a given logical CPU > (the purpose > + of this mechanism is to improve performance). > + > + This setting has no effect on logical CPUs whose minimum P- > state limit > + is directly set to the highest non-turbo P-state or above > it. > + > .. _status_attr: > > ``status`` >