From patchwork Fri Nov 22 09:58:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Yu X-Patchwork-Id: 11257569 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 7D20C930 for ; Fri, 22 Nov 2019 09:48:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FAC72071B for ; Fri, 22 Nov 2019 09:48:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727028AbfKVJr4 (ORCPT ); Fri, 22 Nov 2019 04:47:56 -0500 Received: from mga07.intel.com ([134.134.136.100]:27492 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726500AbfKVJr4 (ORCPT ); Fri, 22 Nov 2019 04:47:56 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Nov 2019 01:47:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,229,1571727600"; d="scan'208";a="259684756" Received: from chenyu-office.sh.intel.com ([10.239.158.173]) by FMSMGA003.fm.intel.com with ESMTP; 22 Nov 2019 01:47:52 -0800 From: Chen Yu To: x86@kernel.org Cc: Thomas Gleixner , Borislav Petkov , Ingo Molnar , "H. Peter Anvin" , Fenghua Yu , Reinette Chatre , Tony Luck , Alexey Dobriyan , Andrew Morton , Michal Hocko , Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Linus Torvalds , Chen Yu , Chen Yu Subject: [PATCH][v4] x86/resctrl: Add task resctrl information display Date: Fri, 22 Nov 2019 17:58:33 +0800 Message-Id: <20191122095833.20861-1-yu.c.chen@intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Monitoring tools that want to find out which resctrl control and monitor groups a task belongs to must currently read the "tasks" file in every group until they locate the process ID. Add an additional file /proc/{pid}/resctrl to provide this information. The output is as followed according to Thomas's suggestion, for example: 1) "" Resctrl is not available. 2) "/" Task is part of the root group, task is not associated to any monitoring group. 3) "/mon_groups/mon0" Task is part of the root group and monitoring group mon0. 4) "/group0" Task is part of control group group0, task is not associated to any monitoring group. 5) "/group0/mon_groups/mon1" Task is part of control group group0 and monitoring group mon1. Tested-by: Jinshi Chen Signed-off-by: Chen Yu --- v2: Reduce indentation level in proc_resctrl_show() according to Boris's suggestion. Create the include/linux/resctrl.h header and declare proc_resctrl_show() in this file, so that other architectures would probably use it in the future. Different architectures should implement architectural specific proc_resctrl_show() accordingly. v3: Return empty string if the resctrl filesystem has not been mounted per Boris's suggestion. Rename the config from CPU_RESCTRL to PROC_CPU_RESCTRL to better represent its usage. Move PROC_CPU_RESCTRL from arch/Kconfig to fs/proc/Kconfig. And let PROC_CPU_RESCTRL to be depended on PROC_FS. v4: According to Thomas's suggestion, changed the output from multiple lines to one single line. --- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 78 ++++++++++++++++++++++++++ fs/proc/Kconfig | 4 ++ fs/proc/base.c | 7 +++ include/linux/resctrl.h | 16 ++++++ 5 files changed, 106 insertions(+) create mode 100644 include/linux/resctrl.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8ef85139553f..252364d18887 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -455,6 +455,7 @@ config X86_CPU_RESCTRL bool "x86 CPU resource control support" depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) select KERNFS + select PROC_CPU_RESCTRL if PROC_FS help Enable x86 CPU resource control support. diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 2e3b06d6bbc6..f8898fe3e85c 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -725,6 +725,84 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of, return ret; } +#ifdef CONFIG_PROC_CPU_RESCTRL + +/* + * A task can only be part of one control + * group and of one monitoring group which + * is associated to that control group. + * So one line is simple and clear enough: + * + * 1) "" + * Resctrl is not available. + * + * 2) "/" + * Task is part of the root group, and it is + * not associated to any monitoring group. + * + * 3) "/mon_groups/mon0" + * Task is part of the root group and monitoring + * group mon0. + * + * 4) "/group0" + * Task is part of control group group0, and it is + * not associated to any monitoring group. + * + * 5) "/group0/mon_groups/mon1" + * Task is part of control group group0 and monitoring + * group mon1. + */ +int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, + struct pid *pid, struct task_struct *tsk) +{ + struct rdtgroup *rdtg; + int ret = 0; + + mutex_lock(&rdtgroup_mutex); + + /* Return empty if resctrl has not been mounted. */ + if (!static_branch_unlikely(&rdt_enable_key)) + goto unlock; + + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { + struct rdtgroup *crg; + + /* + * Task information is only relevant for shareable + * and exclusive groups. + */ + if (rdtg->mode != RDT_MODE_SHAREABLE && + rdtg->mode != RDT_MODE_EXCLUSIVE) + continue; + + if (rdtg->closid != tsk->closid) + continue; + + seq_printf(s, "/%s", rdtg->kn->name); + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, + mon.crdtgrp_list) { + if (tsk->rmid != crg->mon.rmid) + continue; + seq_printf(s, "%smon_groups/%s", + rdtg == &rdtgroup_default ? "" : "/", + crg->kn->name); + break; + } + seq_puts(s, "\n"); + goto unlock; + } + /* + * The above search should succeed. Otherwise return + * with an error. + */ + ret = -ENOENT; +unlock: + mutex_unlock(&rdtgroup_mutex); + + return ret; +} +#endif + static int rdt_last_cmd_status_show(struct kernfs_open_file *of, struct seq_file *seq, void *v) { diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index cb5629bd5fff..ae96a339d24d 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -103,3 +103,7 @@ config PROC_CHILDREN config PROC_PID_ARCH_STATUS def_bool n depends on PROC_FS + +config PROC_CPU_RESCTRL + def_bool n + depends on PROC_FS diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb8..0e4b8bf2b986 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -94,6 +94,7 @@ #include #include #include +#include #include #include "internal.h" #include "fd.h" @@ -3060,6 +3061,9 @@ static const struct pid_entry tgid_base_stuff[] = { #endif #ifdef CONFIG_CGROUPS ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif +#ifdef CONFIG_PROC_CPU_RESCTRL + ONE("resctrl", S_IRUGO, proc_resctrl_show), #endif ONE("oom_score", S_IRUGO, proc_oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), @@ -3460,6 +3464,9 @@ static const struct pid_entry tid_base_stuff[] = { #endif #ifdef CONFIG_CGROUPS ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif +#ifdef CONFIG_PROC_CPU_RESCTRL + ONE("resctrl", S_IRUGO, proc_resctrl_show), #endif ONE("oom_score", S_IRUGO, proc_oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h new file mode 100644 index 000000000000..50b147784d55 --- /dev/null +++ b/include/linux/resctrl.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RESCTRL_H +#define _RESCTRL_H + +#ifdef CONFIG_PROC_CPU_RESCTRL + +#include + +int proc_resctrl_show(struct seq_file *m, + struct pid_namespace *ns, + struct pid *pid, + struct task_struct *tsk); + +#endif + +#endif /* _RESCTRL_H */