From patchwork Fri Jun 11 12:41:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pratik R. Sampat" X-Patchwork-Id: 12315637 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7C190C48BD1 for ; Fri, 11 Jun 2021 12:42:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55CAF6141F for ; Fri, 11 Jun 2021 12:42:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231315AbhFKMoQ (ORCPT ); Fri, 11 Jun 2021 08:44:16 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51932 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231272AbhFKMoP (ORCPT ); Fri, 11 Jun 2021 08:44:15 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 15BCXbCi013278; Fri, 11 Jun 2021 08:42:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=JhedSqjiHJno7nFv+Mq6xGFzMxPYJSPj48RO97RHbFM=; b=lwXL1U1RJxTNN7wpeg8jseEM5Zrm11Rbk1tXTzjC++mH9GH92khEHrkzEjx8hok/WQmV UH1ZRiPGUTU98FwhHHkYSksIb06ib6WUe56hRfeBz5a8BY/lprDK6PuXVX17ikM5lapF G0XK0RS9aAkIK5l1tyVJW4jLK/G/Ku1NzIIPaGVIx05YROkX4vnnDLvUu/qKpJCWZqrV d955k0Iz8Xu3lyA505w0AEUIl2tVDjn4c+YAofxa7cSbItwlrGz4wkWsMPvlSUfFSdVj G35EFtjbeL8Txrk7MupFd4Qt+8a2xqSHhw2crhCYK+x1M2kg69L4JhxCUK6E/xLdD2x1 Uw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3947pcgq04-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 08:42:10 -0400 Received: from m0098410.ppops.net (m0098410.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 15BCY43W016082; Fri, 11 Jun 2021 08:42:10 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 3947pcgpy4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 08:42:09 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 15BCWbUQ004792; Fri, 11 Jun 2021 12:42:07 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma04ams.nl.ibm.com with ESMTP id 3900w8becw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 12:42:07 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 15BCf7fR35652026 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 11 Jun 2021 12:41:07 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6F36252067; Fri, 11 Jun 2021 12:41:59 +0000 (GMT) Received: from pratiks-thinkpad.in.ibm.com (unknown [9.85.83.107]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 982735205A; Fri, 11 Jun 2021 12:41:57 +0000 (GMT) From: "Pratik R. Sampat" To: mpe@ellerman.id.au, shuah@kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org, psampat@linux.ibm.com, pratik.r.sampat@gmail.com Subject: [RFC 1/2] powerpc/cpuidle: Extract IPI based and timer based wakeup latency from idle states Date: Fri, 11 Jun 2021 18:11:53 +0530 Message-Id: <20210611124154.56427-2-psampat@linux.ibm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210611124154.56427-1-psampat@linux.ibm.com> References: <20210611124154.56427-1-psampat@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 4rLkOiwQ1o7QlAmkhVGHrnTpQtroRNa1 X-Proofpoint-ORIG-GUID: -FGEv8xzENIjBrC_GDqSohzEYwtQ_UsR X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-06-11_05:2021-06-11,2021-06-11 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 mlxscore=0 lowpriorityscore=0 phishscore=0 malwarescore=0 bulkscore=0 spamscore=0 suspectscore=0 impostorscore=0 priorityscore=1501 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2106110080 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Introduce a mechanism to fire directed IPIs from a specified source CPU to a specified target CPU and measure the difference in time incurred on wakeup. Also, introduce a mechanism to queue a HR timer on a specified CPU and subsequently measure the time taken to wakeup the CPU. Finally define a simple debugfs interface to control the knobs to fire the IPI and Timer events on specified CPU and view their incurred idle wakeup latencies. Signed-off-by: Pratik R. Sampat --- arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/test-cpuidle_latency.c | 157 +++++++++++++++++++++ lib/Kconfig.debug | 10 ++ 3 files changed, 168 insertions(+) create mode 100644 arch/powerpc/kernel/test-cpuidle_latency.c diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index f66b63e81c3b..56e36e797dd4 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o obj-$(CONFIG_PPC_DAWR) += dawr.o obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o +obj-$(CONFIG_IDLE_LATENCY_SELFTEST) += test-cpuidle_latency.o obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o diff --git a/arch/powerpc/kernel/test-cpuidle_latency.c b/arch/powerpc/kernel/test-cpuidle_latency.c new file mode 100644 index 000000000000..f138011ac225 --- /dev/null +++ b/arch/powerpc/kernel/test-cpuidle_latency.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Module-based API test facility for cpuidle latency using IPIs and timers + */ + +#include +#include +#include + +/* + * IPI based wakeup latencies + * Measure time taken for a CPU to wakeup on a IPI sent from another CPU + * The latency measured also includes the latency of sending the IPI + */ +struct latency { + unsigned int src_cpu; + unsigned int dest_cpu; + ktime_t time_start; + ktime_t time_end; + u64 latency_ns; +} ipi_wakeup; + +static void measure_latency(void *info) +{ + struct latency *v; + ktime_t time_diff; + + v = (struct latency *)info; + v->time_end = ktime_get(); + time_diff = ktime_sub(v->time_end, v->time_start); + v->latency_ns = ktime_to_ns(time_diff); +} + +void run_smp_call_function_test(unsigned int cpu) +{ + ipi_wakeup.src_cpu = smp_processor_id(); + ipi_wakeup.dest_cpu = cpu; + ipi_wakeup.time_start = ktime_get(); + smp_call_function_single(cpu, measure_latency, &ipi_wakeup, 1); +} + +/* + * Timer based wakeup latencies + * Measure time taken for a CPU to wakeup on a timer being armed and fired + */ +struct timer_data { + unsigned int src_cpu; + u64 timeout; + ktime_t time_start; + ktime_t time_end; + struct hrtimer timer; + u64 timeout_diff_ns; +} timer_wakeup; + +static enum hrtimer_restart timer_called(struct hrtimer *hrtimer) +{ + struct timer_data *w; + ktime_t time_diff; + + w = container_of(hrtimer, struct timer_data, timer); + w->time_end = ktime_get(); + + time_diff = ktime_sub(w->time_end, w->time_start); + time_diff = ktime_sub(time_diff, ns_to_ktime(w->timeout)); + w->timeout_diff_ns = ktime_to_ns(time_diff); + return HRTIMER_NORESTART; +} + +static void run_timer_test(unsigned int ns) +{ + hrtimer_init(&timer_wakeup.timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL); + timer_wakeup.timer.function = timer_called; + timer_wakeup.src_cpu = smp_processor_id(); + timer_wakeup.timeout = ns; + timer_wakeup.time_start = ktime_get(); + + hrtimer_start(&timer_wakeup.timer, ns_to_ktime(ns), + HRTIMER_MODE_REL_PINNED); +} + +static struct dentry *dir; + +static int cpu_read_op(void *data, u64 *dest_cpu) +{ + *dest_cpu = ipi_wakeup.dest_cpu; + return 0; +} + +static int cpu_write_op(void *data, u64 value) +{ + run_smp_call_function_test(value); + return 0; +} +DEFINE_SIMPLE_ATTRIBUTE(ipi_ops, cpu_read_op, cpu_write_op, "%llu\n"); + +static int timeout_read_op(void *data, u64 *timeout) +{ + *timeout = timer_wakeup.timeout; + return 0; +} + +static int timeout_write_op(void *data, u64 value) +{ + run_timer_test(value); + return 0; +} +DEFINE_SIMPLE_ATTRIBUTE(timeout_ops, timeout_read_op, timeout_write_op, "%llu\n"); + +static int __init latency_init(void) +{ + struct dentry *temp; + + dir = debugfs_create_dir("latency_test", 0); + if (!dir) { + pr_alert("latency_test: failed to create /sys/kernel/debug/latency_test\n"); + return -1; + } + temp = debugfs_create_file("ipi_cpu_dest", + 0666, + dir, + NULL, + &ipi_ops); + if (!temp) { + pr_alert("latency_test: failed to create /sys/kernel/debug/ipi_cpu_dest\n"); + return -1; + } + debugfs_create_u64("ipi_latency_ns", 0444, dir, &ipi_wakeup.latency_ns); + debugfs_create_u32("ipi_cpu_src", 0444, dir, &ipi_wakeup.src_cpu); + + temp = debugfs_create_file("timeout_expected_ns", + 0666, + dir, + NULL, + &timeout_ops); + if (!temp) { + pr_alert("latency_test: failed to create /sys/kernel/debug/timeout_expected_ns\n"); + return -1; + } + debugfs_create_u64("timeout_diff_ns", 0444, dir, &timer_wakeup.timeout_diff_ns); + debugfs_create_u32("timeout_cpu_src", 0444, dir, &timer_wakeup.src_cpu); + pr_info("Latency Test module loaded\n"); + return 0; +} + +static void __exit latency_cleanup(void) +{ + pr_info("Cleaning up Latency Test module.\n"); + debugfs_remove_recursive(dir); +} + +module_init(latency_init); +module_exit(latency_cleanup); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("IBM Corporation"); +MODULE_DESCRIPTION("Measuring idle latency for IPIs and Timers"); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 417c3d3e521b..70264687e0c2 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1513,6 +1513,16 @@ config DEBUG_KOBJECT If you say Y here, some extra kobject debugging messages will be sent to the syslog. +config IDLE_LATENCY_SELFTEST + tristate "Cpuidle latency selftests" + depends on CPU_IDLE + help + This option provides a kernel module that runs tests using the IPI and + timers to measure latency. + + Say M if you want these self tests to build as a module. + Say N if you are unsure. + config DEBUG_KOBJECT_RELEASE bool "kobject release debugging" depends on DEBUG_OBJECTS_TIMERS From patchwork Fri Jun 11 12:41:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pratik R. Sampat" X-Patchwork-Id: 12315635 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 B5538C48BE0 for ; Fri, 11 Jun 2021 12:42:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97C50613EA for ; Fri, 11 Jun 2021 12:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231437AbhFKMoO (ORCPT ); Fri, 11 Jun 2021 08:44:14 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:22278 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231274AbhFKMoL (ORCPT ); Fri, 11 Jun 2021 08:44:11 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 15BCXCs2161363; Fri, 11 Jun 2021 08:42:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=ErDpu6qFyoOHGIhMeE8dLUL3Jh7OLsiS943qMfLbBr8=; b=KFgrGC8PrJCLLWqRtzUc9sMDnIL67Ob2sU7tb6uBqQEUBqRnlzZAlggUAji2wSnWoTGn AjsnaGCqHbHgnGpn03luGIBgAeRiHwbLaw+S6VXej1QJHSFptohvxGv5xvm+ydWRGcR1 O+JkPy5bCOdiWdpiz3JbAzS8f3ilubvRc/FnWZWp86Q1tyCtbBlA2l2IhVXK9b0qaaB+ b8xChkYwD0Y2HRHMzeH2Ys5rxCDLBnKMEdqmmN3TnlBCuJ1N8wyanCeUP8wJuJaszSml HP3LMM3Ghoalf8F4D4PrQ8LUtY7MM7kWLcq8xPveA6f4da9OGWfaU1G4jGWsckj2Aj/+ bw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 39457f59yc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 08:42:06 -0400 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 15BCXrS0164161; Fri, 11 Jun 2021 08:42:05 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 39457f59x7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 08:42:05 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 15BCWvEo004854; Fri, 11 Jun 2021 12:42:04 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma04ams.nl.ibm.com with ESMTP id 3900w8becy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Jun 2021 12:42:03 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 15BCg1uQ28639498 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 11 Jun 2021 12:42:01 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A23CA52050; Fri, 11 Jun 2021 12:42:01 +0000 (GMT) Received: from pratiks-thinkpad.in.ibm.com (unknown [9.85.83.107]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id CD2C25204F; Fri, 11 Jun 2021 12:41:59 +0000 (GMT) From: "Pratik R. Sampat" To: mpe@ellerman.id.au, shuah@kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org, psampat@linux.ibm.com, pratik.r.sampat@gmail.com Subject: [RFC 2/2] powerpc/selftest: Add support for cpuidle latency measurement Date: Fri, 11 Jun 2021 18:11:54 +0530 Message-Id: <20210611124154.56427-3-psampat@linux.ibm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210611124154.56427-1-psampat@linux.ibm.com> References: <20210611124154.56427-1-psampat@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: wY7oG4CVDe1zknoZWTl8xzJAoQqqpae2 X-Proofpoint-ORIG-GUID: fZJEnuJb8bInLdbCaUJSfxOJN58NchOR X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-06-11_05:2021-06-11,2021-06-11 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 malwarescore=0 bulkscore=0 phishscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 priorityscore=1501 clxscore=1015 suspectscore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2106110080 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The cpuidle latency selftest provides support to systematically extract, analyse and present IPI and timer based wakeup latencies for each CPU and each idle state available on the system. The selftest leverages test-cpuidle_latency module's debugfs interface to interact and extract latency information from the kernel. The selftest inserts the module if already not inserted, disables all the idle states and enables them one by one testing the following: 1. Keeping source CPU constant, iterate through all the CPUS measuring IPI latency for baseline (CPU is busy with cat /dev/random > /dev/null workload) and then when the CPU is allowed to be at rest 2. Iterating through all the CPUs, sending expected timer durations to be equivalent to the residency of the deepest idle state enabled and extracting the difference in time between the time of wakeup and the expected timer duration To run this test specifically: $ sudo make -C tools/testing/selftests \ TARGETS="powerpc/cpuidle_latency" run_tests There are a few optional arguments too that the script can take [-h ] [-m ] [-o ] [-v (run on all cpus)] Default Output location in: tools/testing/selftests/powerpc/cpuidle_latency/cpuidle_latency.log To run the test without re-compiling: $ cd tools/testing/selftest/powerpc/cpuidle_latency/ $ sudo ./cpuidle_latency.sh Signed-off-by: Pratik R. Sampat --- tools/testing/selftests/powerpc/Makefile | 1 + .../powerpc/cpuidle_latency/.gitignore | 2 + .../powerpc/cpuidle_latency/Makefile | 6 + .../cpuidle_latency/cpuidle_latency.sh | 419 ++++++++++++++++++ .../powerpc/cpuidle_latency/settings | 1 + 5 files changed, 429 insertions(+) create mode 100644 tools/testing/selftests/powerpc/cpuidle_latency/.gitignore create mode 100644 tools/testing/selftests/powerpc/cpuidle_latency/Makefile create mode 100755 tools/testing/selftests/powerpc/cpuidle_latency/cpuidle_latency.sh create mode 100644 tools/testing/selftests/powerpc/cpuidle_latency/settings diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile index 0830e63818c1..71ce6fff867d 100644 --- a/tools/testing/selftests/powerpc/Makefile +++ b/tools/testing/selftests/powerpc/Makefile @@ -17,6 +17,7 @@ SUB_DIRS = alignment \ benchmarks \ cache_shape \ copyloops \ + cpuidle_latency \ dscr \ mm \ nx-gzip \ diff --git a/tools/testing/selftests/powerpc/cpuidle_latency/.gitignore b/tools/testing/selftests/powerpc/cpuidle_latency/.gitignore new file mode 100644 index 000000000000..987f8852dc59 --- /dev/null +++ b/tools/testing/selftests/powerpc/cpuidle_latency/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +cpuidle_latency.log diff --git a/tools/testing/selftests/powerpc/cpuidle_latency/Makefile b/tools/testing/selftests/powerpc/cpuidle_latency/Makefile new file mode 100644 index 000000000000..04492b6d2582 --- /dev/null +++ b/tools/testing/selftests/powerpc/cpuidle_latency/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +all: + +TEST_PROGS := cpuidle_latency.sh + +include ../../lib.mk diff --git a/tools/testing/selftests/powerpc/cpuidle_latency/cpuidle_latency.sh b/tools/testing/selftests/powerpc/cpuidle_latency/cpuidle_latency.sh new file mode 100755 index 000000000000..6b55167de488 --- /dev/null +++ b/tools/testing/selftests/powerpc/cpuidle_latency/cpuidle_latency.sh @@ -0,0 +1,419 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# CPU-Idle latency selftest provides support to systematically extract, +# analyse and present IPI and timer based wakeup latencies for each CPU +# and each idle state available on the system by leveraging the +# test-cpuidle_latency module +# +# Author: Pratik R. Sampat + +LOG=cpuidle_latency.log +MODULE=/lib/modules/$(uname -r)/kernel/arch/powerpc/kernel/test-cpuidle_latency.ko + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +VERBOSE=0 + +DISABLE=1 +ENABLE=0 + +helpme() +{ + printf "Usage: $0 [-h] [-todg args] + [-h ] + [-m ] + [-o ] + [-v ] + \n" + exit 2 +} + +parse_arguments() +{ + while getopts ht:m:o:vt:it: arg + do + case $arg in + h) # --help + helpme + ;; + m) # --mod-file + MODULE=$OPTARG + ;; + o) # output log files + LOG=$OPTARG + ;; + v) # Verbose mode - all threads of the CPU + VERBOSE=1 + ;; + \?) + helpme + ;; + esac + done +} + +ins_mod() +{ + debugfs_file=/sys/kernel/debug/latency_test/ipi_latency_ns + # Check if the module is already loaded + if [ -f "$debugfs_file" ]; then + printf "Module already loaded\n\n" + return 0 + fi + # Try to load the module + if [ ! -f "$MODULE" ]; then + printf "$MODULE module does not exist. Exitting\n" + exit $ksft_skip + fi + printf "Inserting $MODULE module\n\n" + insmod $MODULE + if [ $? != 0 ]; then + printf "Insmod $MODULE failed\n" + exit $ksft_skip + fi +} + +compute_average() +{ + arr=("$@") + sum=0 + size=${#arr[@]} + if [ $size == 0 ]; then + avg=0 + return 1 + fi + for i in "${arr[@]}" + do + sum=$((sum + i)) + done + avg=$((sum/size)) +} + +cpu_is_online() +{ + cpu=$1 + if [ ! -f "/sys/devices/system/cpu/cpu$cpu/online" ]; then + echo 1 + return + fi + status=$(cat /sys/devices/system/cpu/cpu$cpu/online) + echo $status +} + +# Perform operation on each CPU for the given state +# $1 - Operation: enable (0) / disable (1) +# $2 - State to enable +op_state() +{ + for ((cpu=0; cpu /sys/devices/system/cpu/cpu$cpu/cpuidle/state$2/disable + done +} + +cpuidle_enable_state() +{ + state=$1 + op_state $ENABLE $state +} + +cpuidle_disable_state() +{ + state=$1 + op_state $DISABLE $state +} + +# Enable/Disable all stop states for all CPUs +# $1 - Operation: enable (0) / disable (1) +op_cpuidle() +{ + for ((state=0; state /dev/null & + task_pid=$! + # Wait for the workload to achieve 100% CPU usage + sleep 1 + fi + taskset 0x1 echo $dest_cpu > /sys/kernel/debug/latency_test/ipi_cpu_dest + ipi_latency=$(cat /sys/kernel/debug/latency_test/ipi_latency_ns) + src_cpu=$(cat /sys/kernel/debug/latency_test/ipi_cpu_src) + if [ "$1" = "baseline" ]; then + kill $task_pid + wait $task_pid 2>/dev/null + fi +} + +# Incrementally Enable idle states one by one and compute the latency +run_ipi_tests() +{ + extract_latency + # Disable idle states for CPUs + op_cpuidle $DISABLE + + declare -a avg_arr + echo -e "--IPI Latency Test---" | tee -a $LOG + + echo -e "--Baseline IPI Latency measurement: CPU Busy--" >> $LOG + printf "%s %10s %12s\n" "SRC_CPU" "DEST_CPU" "IPI_Latency(ns)" >> $LOG + for cpu in "${core_arr[@]}" + do + local cpu_status=$(cpu_is_online $cpu) + if [ $cpu_status == 0 ]; then + continue + fi + ipi_test_once "baseline" $cpu + printf "%-3s %10s %12s\n" $src_cpu $cpu $ipi_latency >> $LOG + # Skip computing latency average from the source CPU to avoid bias + element_in "$cpu" "${first_core_arr[@]}" + if [ $? == 0 ]; then + continue + fi + avg_arr+=($ipi_latency) + done + compute_average "${avg_arr[@]}" + echo -e "Baseline Avg IPI latency(ns): $avg" | tee -a $LOG + + for ((state=0; state> $LOG + cpuidle_enable_state $state + printf "%s %10s %12s\n" "SRC_CPU" "DEST_CPU" "IPI_Latency(ns)" >> $LOG + for cpu in "${core_arr[@]}" + do + local cpu_status=$(cpu_is_online $cpu) + if [ $cpu_status == 0 ]; then + continue + fi + # Running IPI test and logging results + sleep 1 + ipi_test_once "test" $cpu + printf "%-3s %10s %12s\n" $src_cpu $cpu $ipi_latency >> $LOG + # Skip computing latency average from the source CPU to avoid bias + element_in "$cpu" "${first_core_arr[@]}" + if [ $? == 0 ]; then + continue + fi + avg_arr+=($ipi_latency) + done + compute_average "${avg_arr[@]}" + echo -e "Expected IPI latency(ns): ${latency_arr[$state]}" >> $LOG + echo -e "Observed Avg IPI latency(ns) - State ${state_name_arr[$state]}: $avg" | tee -a $LOG + cpuidle_disable_state $state + done +} + +# Extract the residency in microseconds and convert to nanoseconds. +# Add 200 ns so that the timer stays for a little longer than the residency +extract_residency() +{ + for ((state=0; state /dev/null & + task_pid=$! + # Wait for the workload to achieve 100% CPU usage + sleep 1 + fi + taskset -c $dest_cpu echo $3 > /sys/kernel/debug/latency_test/timeout_expected_ns + # Wait for the result to populate + sleep 0.1 + timeout_diff=$(cat /sys/kernel/debug/latency_test/timeout_diff_ns) + src_cpu=$(cat /sys/kernel/debug/latency_test/timeout_cpu_src) + if [ "$1" = "baseline" ]; then + kill $task_pid + wait $task_pid 2>/dev/null + fi +} + +run_timeout_tests() +{ + extract_residency + # Disable idle states for all CPUs + op_cpuidle $DISABLE + + declare -a avg_arr + echo -e "\n--Timeout Latency Test--" | tee -a $LOG + + echo -e "--Baseline Timeout Latency measurement: CPU Busy--" >> $LOG + printf "%s %10s %10s\n" "Wakeup_src" "Baseline_delay(ns)">> $LOG + for cpu in "${core_arr[@]}" + do + local cpu_status=$(cpu_is_online $cpu) + if [ $cpu_status == 0 ]; then + continue + fi + timeout_test_once "baseline" $cpu 1000000 + printf "%-3s %13s\n" $src_cpu $timeout_diff >> $LOG + avg_arr+=($timeout_diff) + done + compute_average "${avg_arr[@]}" + echo -e "Baseline Avg timeout diff(ns): $avg" | tee -a $LOG + + for ((state=0; state> $LOG + cpuidle_enable_state $state + printf "%s %10s %10s\n" "Wakeup_src" "Baseline_delay(ns)" "Delay(ns)" >> $LOG + for cpu in "${core_arr[@]}" + do + local cpu_status=$(cpu_is_online $cpu) + if [ $cpu_status == 0 ]; then + continue + fi + timeout_test_once "test" $cpu 1000000 + printf "%-3s %13s %18s\n" $src_cpu $baseline_timeout_diff $timeout_diff >> $LOG + avg_arr+=($timeout_diff) + done + compute_average "${avg_arr[@]}" + echo -e "Expected timeout(ns): ${residency_arr[$state]}" >> $LOG + echo -e "Observed Avg timeout diff(ns) - State ${state_name_arr[$state]}: $avg" | tee -a $LOG + cpuidle_disable_state $state + done +} + +declare -a residency_arr +declare -a latency_arr +declare -a core_arr +declare -a first_core_arr +declare -a state_name_arr + +parse_arguments $@ + +rm -f $LOG +touch $LOG +NUM_CPUS=$(nproc --all) +NUM_STATES=$(ls -1 /sys/devices/system/cpu/cpu0/cpuidle/ | wc -l) + +extract_core_information +extract_state_information + +ins_mod $MODULE + +run_ipi_tests +run_timeout_tests + +# Enable all idle states for all CPUs +op_cpuidle $ENABLE +printf "Removing $MODULE module\n" +printf "Full Output logged at: $LOG\n" +rmmod $MODULE + diff --git a/tools/testing/selftests/powerpc/cpuidle_latency/settings b/tools/testing/selftests/powerpc/cpuidle_latency/settings new file mode 100644 index 000000000000..e7b9417537fb --- /dev/null +++ b/tools/testing/selftests/powerpc/cpuidle_latency/settings @@ -0,0 +1 @@ +timeout=0