From patchwork Thu Jul 30 05:32:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gautham R Shenoy X-Patchwork-Id: 11692357 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3A15E722 for ; Thu, 30 Jul 2020 05:33:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BD322084D for ; Thu, 30 Jul 2020 05:33:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728630AbgG3FdV (ORCPT ); Thu, 30 Jul 2020 01:33:21 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:19182 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbgG3FdU (ORCPT ); Thu, 30 Jul 2020 01:33:20 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06U5X3Gg179093; Thu, 30 Jul 2020 01:33:18 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jy8whq86-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 01:33:18 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06U5XIST179933; Thu, 30 Jul 2020 01:33:18 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jy8whq7n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 01:33:18 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06U5OQIM030866; Thu, 30 Jul 2020 05:33:17 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma04dal.us.ibm.com with ESMTP id 32gcq1ss2x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 05:33:17 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06U5XGQg48300468 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Jul 2020 05:33:16 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5FCBDAE067; Thu, 30 Jul 2020 05:33:16 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BE412AE05F; Thu, 30 Jul 2020 05:33:15 +0000 (GMT) Received: from sofia.ibm.com (unknown [9.102.0.230]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 30 Jul 2020 05:33:15 +0000 (GMT) Received: by sofia.ibm.com (Postfix, from userid 1000) id D80F82E2EB8; Thu, 30 Jul 2020 11:03:09 +0530 (IST) From: "Gautham R. Shenoy" To: Nicholas Piggin , Anton Blanchard , Nathan Lynch , Michael Ellerman , Michael Neuling , Vaidyanathan Srinivasan Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, "Gautham R. Shenoy" Subject: [PATCH v3 1/3] cpuidle-pseries: Set the latency-hint before entering CEDE Date: Thu, 30 Jul 2020 11:02:55 +0530 Message-Id: <1596087177-30329-2-git-send-email-ego@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1596087177-30329-1-git-send-email-ego@linux.vnet.ibm.com> References: <1596087177-30329-1-git-send-email-ego@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-30_03:2020-07-29,2020-07-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 phishscore=0 mlxscore=0 bulkscore=0 malwarescore=0 adultscore=0 clxscore=1015 lowpriorityscore=0 suspectscore=0 mlxlogscore=850 spamscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007300042 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: "Gautham R. Shenoy" As per the PAPR, each H_CEDE call is associated with a latency-hint to be passed in the VPA field "cede_latency_hint". The CEDE states that we were implicitly entering so far is CEDE with latency-hint = 0. This patch explicitly sets the latency hint corresponding to the CEDE state that we are currently entering. While at it, we save the previous hint, to be restored once we wakeup from CEDE. This will be required in the future when we expose extended-cede states through the cpuidle framework, where each of them will have a different cede-latency hint. Signed-off-by: Gautham R. Shenoy --- v2-->v3 : Got rid of the usused NR_CEDE_STATES definition drivers/cpuidle/cpuidle-pseries.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c index 3e058ad2..f5865a2 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -86,19 +86,26 @@ static void check_and_cede_processor(void) } } +#define NR_DEDICATED_STATES 2 /* snooze, CEDE */ + +u8 cede_latency_hint[NR_DEDICATED_STATES]; static int dedicated_cede_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { + u8 old_latency_hint; pseries_idle_prolog(); get_lppaca()->donate_dedicated_cpu = 1; + old_latency_hint = get_lppaca()->cede_latency_hint; + get_lppaca()->cede_latency_hint = cede_latency_hint[index]; HMT_medium(); check_and_cede_processor(); local_irq_disable(); get_lppaca()->donate_dedicated_cpu = 0; + get_lppaca()->cede_latency_hint = old_latency_hint; pseries_idle_epilog(); @@ -130,7 +137,7 @@ static int shared_cede_loop(struct cpuidle_device *dev, /* * States for dedicated partition case. */ -static struct cpuidle_state dedicated_states[] = { +static struct cpuidle_state dedicated_states[NR_DEDICATED_STATES] = { { /* Snooze */ .name = "snooze", .desc = "snooze", @@ -233,7 +240,7 @@ static int pseries_idle_probe(void) max_idle_state = ARRAY_SIZE(shared_states); } else { cpuidle_state_table = dedicated_states; - max_idle_state = ARRAY_SIZE(dedicated_states); + max_idle_state = NR_DEDICATED_STATES; } } else return -ENODEV;