From patchwork Tue Jun 5 21:42:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Srinivas Pandruvada X-Patchwork-Id: 10449283 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0C59060467 for ; Tue, 5 Jun 2018 21:43:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0225228B20 for ; Tue, 5 Jun 2018 21:43:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E91A029533; Tue, 5 Jun 2018 21:43:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9379B28B20 for ; Tue, 5 Jun 2018 21:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751698AbeFEVmw (ORCPT ); Tue, 5 Jun 2018 17:42:52 -0400 Received: from mga04.intel.com ([192.55.52.120]:37416 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752063AbeFEVmv (ORCPT ); Tue, 5 Jun 2018 17:42:51 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jun 2018 14:42:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,479,1520924400"; d="scan'208";a="47023741" Received: from spandruv-desk.jf.intel.com ([10.54.75.31]) by orsmga008.jf.intel.com with ESMTP; 05 Jun 2018 14:42:49 -0700 From: Srinivas Pandruvada To: lenb@kernel.org, rjw@rjwysocki.net, mgorman@techsingularity.net Cc: peterz@infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, viresh.kumar@linaro.org, ggherdovich@suse.cz, Srinivas Pandruvada Subject: [PATCH 2/4] cpufreq: intel_pstate: HWP boost performance on IO wakeup Date: Tue, 5 Jun 2018 14:42:40 -0700 Message-Id: <20180605214242.62156-3-srinivas.pandruvada@linux.intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180605214242.62156-1-srinivas.pandruvada@linux.intel.com> References: <20180605214242.62156-1-srinivas.pandruvada@linux.intel.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This change uses SCHED_CPUFREQ_IOWAIT flag to boost HWP performance. Since SCHED_CPUFREQ_IOWAIT flag is set frequently, we don't start boosting steps unless we see two consecutive flags in two ticks. This avoids boosting due to IO because of regular system activities. To avoid synchronization issues, the actual processing of the flag is done on the local CPU callback. Reported-by: Mel Gorman Tested-by: Giovanni Gherdovich Signed-off-by: Srinivas Pandruvada --- drivers/cpufreq/intel_pstate.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 3949e3861f55..5b2b6b6d1ff4 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -223,6 +223,8 @@ struct global_params { * operation * @hwp_req_cached: Cached value of the last HWP Request MSR * @hwp_cap_cached: Cached value of the last HWP Capabilities MSR + * @last_io_update: Last time when IO wake flag was set + * @sched_flags: Store scheduler flags for possible cross CPU update * @hwp_boost_min: Last HWP boosted min performance * * This structure stores per CPU instance data for all CPUs. @@ -258,6 +260,8 @@ struct cpudata { s16 epp_saved; u64 hwp_req_cached; u64 hwp_cap_cached; + u64 last_io_update; + unsigned int sched_flags; u32 hwp_boost_min; }; @@ -1460,9 +1464,44 @@ static inline void intel_pstate_hwp_boost_down(struct cpudata *cpu) cpu->last_update = cpu->sample.time; } +static inline void intel_pstate_update_util_hwp_local(struct cpudata *cpu, + u64 time) +{ + cpu->sample.time = time; + + if (cpu->sched_flags & SCHED_CPUFREQ_IOWAIT) { + bool do_io = false; + + cpu->sched_flags = 0; + /* + * Set iowait_boost flag and update time. Since IO WAIT flag + * is set all the time, we can't just conclude that there is + * some IO bound activity is scheduled on this CPU with just + * one occurrence. If we receive at least two in two + * consecutive ticks, then we treat as boost candidate. + */ + if (time_before64(time, cpu->last_io_update + 2 * TICK_NSEC)) + do_io = true; + + cpu->last_io_update = time; + + if (do_io) + intel_pstate_hwp_boost_up(cpu); + + } else { + intel_pstate_hwp_boost_down(cpu); + } +} + static inline void intel_pstate_update_util_hwp(struct update_util_data *data, u64 time, unsigned int flags) { + struct cpudata *cpu = container_of(data, struct cpudata, update_util); + + cpu->sched_flags |= flags; + + if (smp_processor_id() == cpu->cpu) + intel_pstate_update_util_hwp_local(cpu, time); } static inline void intel_pstate_calc_avg_perf(struct cpudata *cpu)