From e79f15a4598c1f3f3f7f3319ca308c63c91fdaf2 Mon Sep 17 00:00:00 2001 From: Chen Yu Date: Wed, 15 Jan 2020 17:28:51 +0800 Subject: [PATCH] x86/resctrl: Add task resctrl information display 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}/cpu_resctrl_groups to provide this information: 1) res: mon: resctrl is not available. 2) res:/ mon: Task is part of the root resctrl control group, and it is not associated to any monitor group. 3) res:/ mon:mon0 Task is part of the root resctrl control group and monitor group mon0. 4) res:group0 mon: Task is part of resctrl control group group0, and it is not associated to any monitor group. 5) res:group0 mon:mon1 Task is part of resctrl control group group0 and monitor group mon1. Signed-off-by: Chen Yu Signed-off-by: Borislav Petkov Tested-by: Jinshi Chen Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com --- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 86 ++++++++++++++++++++++++++ fs/proc/Kconfig | 4 ++ fs/proc/base.c | 7 +++ include/linux/resctrl.h | 14 +++++ 5 files changed, 112 insertions(+) create mode 100644 include/linux/resctrl.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5e8949953660..6e17a68c7d77 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -456,6 +456,7 @@ 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 205925d802d8..5b3ba83013b5 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -729,6 +729,92 @@ 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 resctrl control group and of one monitor + * group which is associated to that control group. + * + * 1) res: + * mon: + * + * resctrl is not available. + * + * 2) res:/ + * mon: + * + * Task is part of the root resctrl control group, and it is not associated + * to any monitor group. + * + * 3) res:/ + * mon:mon0 + * + * Task is part of the root resctrl control group and monitor group mon0. + * + * 4) res:group0 + * mon: + * + * Task is part of resctrl control group group0, and it is not associated + * to any monitor group. + * + * 5) res:group0 + * mon:mon1 + * + * Task is part of resctrl control group group0 and monitor 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)) { + seq_puts(s, "res:\nmon:\n"); + 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, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "", + rdtg->kn->name); + seq_puts(s, "mon:"); + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, + mon.crdtgrp_list) { + if (tsk->rmid != crg->mon.rmid) + continue; + seq_printf(s, "%s", crg->kn->name); + break; + } + seq_putc(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 733881a6387b..27ef84d99f59 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..bbffd654bb0e 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("cpu_resctrl_groups", 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("cpu_resctrl_groups", 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..daf5cf64c6a6 --- /dev/null +++ b/include/linux/resctrl.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RESCTRL_H +#define _RESCTRL_H + +#ifdef CONFIG_PROC_CPU_RESCTRL + +int proc_resctrl_show(struct seq_file *m, + struct pid_namespace *ns, + struct pid *pid, + struct task_struct *tsk); + +#endif + +#endif /* _RESCTRL_H */ -- 2.20.1