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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 66449C43463 for ; Mon, 21 Sep 2020 06:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1288F20756 for ; Mon, 21 Sep 2020 06:40:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="MWaIiB8Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726366AbgIUGkz (ORCPT ); Mon, 21 Sep 2020 02:40:55 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:28730 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726011AbgIUGky (ORCPT ); Mon, 21 Sep 2020 02:40:54 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08L6Uwac154079; Mon, 21 Sep 2020 02:40:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id; s=pp1; bh=YukWaNNrYbEYncAIP32I5JpWJB8+m1YD2MhzkKKYNKo=; b=MWaIiB8Ym0/X7a0CcCQ3Lgxas95h5uZhiTi8Hn/9rcrr2DyMOOS312mxkzlr1juxtpdw nrUqI8//syWMRxTJu6R7/Y0ewnT98O8Y16YjbGN1LLFQqtWdiqeqGDsT2obVS3UET2ze bwig2WZPkkY9Kgehkog0qIZeC7+o+4Ya0u6NOG9ECz79fSu6c1eJSmFRuBlAxrixJs0I 5H3ZOC0gnQkCFGIXKSbFnDF0YtqSi0LhVND1HstUzHG4vScuHAnVpbhutJG5oXTCILNa s+zGI5eH+PCYA0CKqEyjugNbu9NhzGS1tDo0sAn3OIab6Mt+fvFXGEeQO+PLTQL/fVN1 YQ== Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0b-001b2d01.pphosted.com with ESMTP id 33pp8eh8fr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 21 Sep 2020 02:40:36 -0400 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 08L6bgUV015743; Mon, 21 Sep 2020 06:40:34 GMT Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by ppma02fra.de.ibm.com with ESMTP id 33n9m80vhu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 21 Sep 2020 06:40:34 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 08L6eWII28574058 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 21 Sep 2020 06:40:32 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2DD5252051; Mon, 21 Sep 2020 06:40:32 +0000 (GMT) Received: from bostonp9.aus.stglabs.ibm.com (unknown [9.3.23.179]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id A924352050; Mon, 21 Sep 2020 06:40:30 +0000 (GMT) From: Abhishek Goel To: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net, daniel.lezcano@linaro.org, mpe@ellerman.id.au, ego@linux.vnet.ibm.com, rdunlap@infradead.org, dan.carpenter@oracle.com, Nathan.Fontenot@amd.com, Abhishek Goel Subject: [RFC v2] cpuidle : Add support for pseudo-cpuidle driver Date: Mon, 21 Sep 2020 01:39:51 -0500 Message-Id: <20200921063951.131529-1-huntbag@linux.vnet.ibm.com> X-Mailer: git-send-email 2.17.1 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-21_01:2020-09-21,2020-09-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 clxscore=1011 impostorscore=0 bulkscore=0 lowpriorityscore=0 phishscore=0 adultscore=0 spamscore=0 priorityscore=1501 mlxscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009210047 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This option adds support for a testing cpuidle driver, which allows user to define custom idle states with their respective latencies and residencies. This is useful for testing the behaviour of governors on customized set of idle states. This can be used as of now by hard-coding the customized set of cpuidle states in the driver. Will add the capability of this driver to be used as a module in subsequent patches. Original idea and discussion for this patch can be found at: https://lkml.org/lkml/2019/12/17/655 Signed-off-by: Abhishek Goel --- v1-> v2 : Includes minor changes adapted from reviews. Also, there was a divergence from expected behaviour of idle loop in v1. That has been fixed. drivers/cpuidle/Kconfig | 9 ++ drivers/cpuidle/Makefile | 1 + drivers/cpuidle/cpuidle-test.c | 283 +++++++++++++++++++++++++++++++++ 3 files changed, 293 insertions(+) create mode 100644 drivers/cpuidle/cpuidle-test.c diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index c0aeedd66f02..1a0f227d61d6 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -71,6 +71,15 @@ config HALTPOLL_CPUIDLE before halting in the guest (more efficient than polling in the host via halt_poll_ns for some scenarios). +config TEST_CPUIDLE + tristate "cpuidle test driver" + default n + help + This option enables a testing cpuidle driver, which allows the user + to define custom idle states with their respective latencies & residencies. + This is useful for testing the behaviour of governors on different + sets of idle states. + endif config ARCH_NEEDS_CPU_IDLE_COUPLED diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index f07800cbb43f..68ea7dc257b5 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o obj-$(CONFIG_DT_IDLE_STATES) += dt_idle_states.o obj-$(CONFIG_ARCH_HAS_CPU_RELAX) += poll_state.o obj-$(CONFIG_HALTPOLL_CPUIDLE) += cpuidle-haltpoll.o +obj-$(CONFIG_TEST_CPUIDLE) += cpuidle-test.o ################################################################################## # ARM SoC drivers diff --git a/drivers/cpuidle/cpuidle-test.c b/drivers/cpuidle/cpuidle-test.c new file mode 100644 index 000000000000..45605f142dab --- /dev/null +++ b/drivers/cpuidle/cpuidle-test.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * cpuidle-test - Test driver for cpuidle. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CPUIDLE_STATE_MAX 10 +#define MAX_PARAM_LENGTH 100 + +static unsigned int nr_states = 4; +static unsigned int sim_type = 1; +static char name[MAX_PARAM_LENGTH]; +static char latency_us[MAX_PARAM_LENGTH]; +static char residency_us[MAX_PARAM_LENGTH]; + + +module_param(nr_states, uint, 0644); +module_param(sim_type, uint, 0644); +module_param_string(name, name, MAX_PARAM_LENGTH, 0644); +module_param_string(latency_us, latency_us, MAX_PARAM_LENGTH, 0644); +module_param_string(residency_us, residency_us, MAX_PARAM_LENGTH, 0644); + +static struct cpuidle_driver test_cpuidle_driver = { + .name = "test_cpuidle", + .owner = THIS_MODULE, +}; + +static struct cpuidle_state *cpuidle_state_table __read_mostly; + +static struct cpuidle_device __percpu *test_cpuidle_devices; +static enum cpuhp_state test_hp_idlestate; + + +static int __cpuidle idle_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + u64 time_start; + + local_irq_enable(); + if (!current_set_polling_and_test()) { + while (!need_resched()) + cpu_relax(); + } + + time_start = local_clock(); + + /* + * Currently, this while loop which is intended to introduce latency + * for corresponding idle states, may not necessarily execute + * completely if there is a interrupt in betweeen. This need to be + * worked upon to distinguish among idle states. + */ + while (local_clock() - time_start < drv->states[index].exit_latency) { + } + + current_clr_polling(); + + return index; +} + +static struct cpuidle_state cpuidle_states[CPUIDLE_STATE_MAX] = { + { /* Snooze */ + .name = "snooze", + .exit_latency = 0, + .target_residency = 0, + .enter = idle_loop }, +}; + +static struct cpuidle_state cpuidle_states_ppc[] = { + { .name = "snooze", + .exit_latency = 0, + .target_residency = 0, + .enter = idle_loop }, + { + .name = "stop0", + .exit_latency = 2, + .target_residency = 20, + .enter = idle_loop }, + { + .name = "stop1", + .exit_latency = 5, + .target_residency = 50, + .enter = idle_loop }, + { + .name = "stop2", + .exit_latency = 10, + .target_residency = 100, + .enter = idle_loop }, +}; + +static struct cpuidle_state cpuidle_states_intel[] = { + { .name = "poll", + .exit_latency = 0, + .target_residency = 0, + .enter = idle_loop }, + { + .name = "c1", + .exit_latency = 2, + .target_residency = 2, + .enter = idle_loop }, + { + .name = "c1e", + .exit_latency = 10, + .target_residency = 20, + .enter = idle_loop }, + { + .name = "c3", + .exit_latency = 80, + .target_residency = 211, + .enter = idle_loop }, +}; + +static int cpuidle_cpu_online(unsigned int cpu) +{ + struct cpuidle_device *dev; + + dev = per_cpu_ptr(test_cpuidle_devices, cpu); + if (!dev->registered) { + dev->cpu = cpu; + if (cpuidle_register_device(dev)) { + pr_notice("cpuidle_register_device %d failed!\n", cpu); + return -EIO; + } + } + + return 0; +} + +static int cpuidle_cpu_dead(unsigned int cpu) +{ + struct cpuidle_device *dev; + + dev = per_cpu_ptr(test_cpuidle_devices, cpu); + if (dev->registered) + cpuidle_unregister_device(dev); + + return 0; +} + +static int cpuidle_driver_init(void) +{ + int idle_state; + struct cpuidle_driver *drv = &test_cpuidle_driver; + + drv->state_count = 0; + + for (idle_state = 0; idle_state < nr_states; ++idle_state) { + /* Is the state not enabled? */ + if (cpuidle_state_table[idle_state].enter == NULL) + continue; + + drv->states[drv->state_count] = /* structure copy */ + cpuidle_state_table[idle_state]; + + drv->state_count += 1; + } + + return 0; +} + +static int add_cpuidle_states(void) +{ + /* Parse the module param and initialize the idle states here + * in cpuidle_state_table. + */ + char *this_param; + char *input_name = name; + char *input_res = residency_us; + char *input_lat = latency_us; + int index = 1; + long temp; + int rc; + + switch (sim_type) { + case 1: + cpuidle_state_table = cpuidle_states_ppc; + return 0; + case 2: + cpuidle_state_table = cpuidle_states_intel; + return 0; + case 3: + break; + default: + pr_warn("Sim value out of bound\n"); + break; + } + + if (strnlen(input_name, MAX_PARAM_LENGTH)) { + while ((this_param = strsep(&input_name, ",")) && index <= nr_states) { + strcpy(cpuidle_states[index].name, this_param); + cpuidle_states[index].enter = idle_loop; + index++; + } + } + + if (strnlen(input_res, MAX_PARAM_LENGTH)) { + index = 1; + while ((this_param = strsep(&input_res, ",")) && index <= nr_states) { + rc = kstrtol(this_param, 10, &temp); + cpuidle_states[index].target_residency = temp; + index++; + } + } + + if (strnlen(input_lat, MAX_PARAM_LENGTH)) { + index = 1; + while ((this_param = strsep(&input_lat, ",")) && index <= nr_states) { + rc = kstrtol(this_param, 10, &temp); + cpuidle_states[index].exit_latency = temp; + index++; + } + } + + cpuidle_state_table = cpuidle_states; + return nr_states; +} + +static void test_cpuidle_uninit(void) +{ + if (test_hp_idlestate) + cpuhp_remove_state(test_hp_idlestate); + cpuidle_unregister_driver(&test_cpuidle_driver); + + free_percpu(test_cpuidle_devices); + test_cpuidle_devices = NULL; +} + +static int __init test_cpuidle_init(void) +{ + int retval; + + add_cpuidle_states(); + cpuidle_driver_init(); + retval = cpuidle_register(&test_cpuidle_driver, NULL); + if (retval) { + printk(KERN_DEBUG "Registration of test driver failed.\n"); + return retval; + } + + test_cpuidle_devices = alloc_percpu(struct cpuidle_device); + if (test_cpuidle_devices == NULL) { + cpuidle_unregister_driver(&test_cpuidle_driver); + return -ENOMEM; + } + + retval = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "cpuidle/powernv:online", + cpuidle_cpu_online, + cpuidle_cpu_dead); + + if (retval < 0) { + test_cpuidle_uninit(); + } else { + test_hp_idlestate = retval; + retval = 0; + } + + return retval; +} + +static void __exit test_cpuidle_exit(void) +{ + test_cpuidle_uninit(); +} + +module_init(test_cpuidle_init); +module_exit(test_cpuidle_exit); +MODULE_DESCRIPTION("Test Cpuidle Driver"); +MODULE_AUTHOR("Abhishek Goel"); +MODULE_LICENSE("GPL"); + -- 2.17.1