From patchwork Tue Jan 22 16:42:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Quentin Perret X-Patchwork-Id: 10775867 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-2.web.codeaurora.org (Postfix) with ESMTP id B65CD13B4 for ; Tue, 22 Jan 2019 16:43:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A583B2B409 for ; Tue, 22 Jan 2019 16:43:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2E802B430; Tue, 22 Jan 2019 16:43:02 +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=ham 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 936CE2B414 for ; Tue, 22 Jan 2019 16:43:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729103AbfAVQnA (ORCPT ); Tue, 22 Jan 2019 11:43:00 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:57224 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729031AbfAVQnA (ORCPT ); Tue, 22 Jan 2019 11:43:00 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 01D41A78; Tue, 22 Jan 2019 08:43:00 -0800 (PST) Received: from queper01-lin.cambridge.arm.com (queper01-lin.cambridge.arm.com [10.1.195.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A2993F6A8; Tue, 22 Jan 2019 08:42:58 -0800 (PST) From: Quentin Perret To: rafael@kernel.org, peterz@infradead.org, mingo@redhat.com Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, dietmar.eggemann@arm.com, gregkh@linuxfoundation.org, quentin.perret@arm.com Subject: [PATCH v2] PM / EM: Expose the Energy Model in debugfs Date: Tue, 22 Jan 2019 16:42:47 +0000 Message-Id: <20190122164247.19439-1-quentin.perret@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 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 The recently introduced Energy Model (EM) framework manages power cost tables of CPUs. These tables are currently only visible from kernel space. However, in order to debug the behaviour of subsystems that use the EM (EAS for example), it is often required to know what the power costs are from userspace. For this reason, introduce under /sys/kernel/debug/energy_model a set of directories representing the performance domains of the system. Each performance domain contains a set of sub-directories representing the different capacity states (cs) and their attributes, as well as a file exposing the related CPUs. The resulting hierarchy is as follows on Arm juno r0 for example: /sys/kernel/debug/energy_model ├── pd0 │   ├── cpus │   ├── cs:450000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:575000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:700000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   ├── cs:775000 │   │   ├── cost │   │   ├── frequency │   │   └── power │   └── cs:850000 │   ├── cost │   ├── frequency │   └── power └── pd1 ├── cpus ├── cs:1100000 │   ├── cost │   ├── frequency │   └── power ├── cs:450000 │   ├── cost │   ├── frequency │   └── power ├── cs:625000 │   ├── cost │   ├── frequency │   └── power ├── cs:800000 │   ├── cost │   ├── frequency │   └── power └── cs:950000 ├── cost ├── frequency └── power Signed-off-by: Quentin Perret Reviewed-by: Greg Kroah-Hartman --- V2: removed check on return value of debugfs_create_* (Greg KH) --- kernel/power/energy_model.c | 57 +++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index d9dc2c38764a..7d66ee68aaaf 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -23,6 +24,60 @@ static DEFINE_PER_CPU(struct em_perf_domain *, em_data); */ static DEFINE_MUTEX(em_pd_mutex); +#ifdef CONFIG_DEBUG_FS +static struct dentry *rootdir; + +static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +{ + struct dentry *d; + char name[24]; + + snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + + /* Create per-cs directory */ + d = debugfs_create_dir(name, pd); + debugfs_create_ulong("frequency", 0444, d, &cs->frequency); + debugfs_create_ulong("power", 0444, d, &cs->power); + debugfs_create_ulong("cost", 0444, d, &cs->cost); +} + +static int em_debug_cpus_show(struct seq_file *s, void *unused) +{ + seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private))); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); + +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +{ + struct dentry *d; + char name[8]; + int i; + + snprintf(name, sizeof(name), "pd%d", cpu); + + /* Create the directory of the performance domain */ + d = debugfs_create_dir(name, rootdir); + + debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + + /* Create a sub-directory for each capacity state */ + for (i = 0; i < pd->nr_cap_states; i++) + em_debug_create_cs(&pd->table[i], d); +} + +static int __init em_debug_init(void) +{ + /* Create /sys/kernel/debug/energy_model directory */ + rootdir = debugfs_create_dir("energy_model", NULL); + + return 0; +} +core_initcall(em_debug_init); +#else /* CONFIG_DEBUG_FS */ +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +#endif static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, struct em_data_callback *cb) { @@ -102,6 +157,8 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, pd->nr_cap_states = nr_states; cpumask_copy(to_cpumask(pd->cpus), span); + em_debug_create_pd(pd, cpu); + return pd; free_cs_table: