diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 56e3445972c3..3d6c8116254d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -457,6 +457,7 @@ 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/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index e49b77283924..181c992f448c 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -57,6 +57,7 @@ static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) } DECLARE_STATIC_KEY_FALSE(rdt_enable_key); +DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); /** * struct mon_evt - Entry in the event list of a resource diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 397206f23d14..773124b0e18a 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -514,7 +514,7 @@ void mbm_handle_overflow(struct work_struct *work) mutex_lock(&rdtgroup_mutex); - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) goto out_unlock; d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]); @@ -543,7 +543,7 @@ void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms) unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) return; cpu = cpumask_any(&dom->cpu_mask); dom->mbm_work_cpu = cpu; diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index dac7209a0708..1504bcabc63c 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -532,11 +532,15 @@ static void move_myself(struct callback_head *head) kfree(rdtgrp); } + if (unlikely(current->flags & PF_EXITING)) + goto out; + preempt_disable(); /* update PQR_ASSOC MSR to make resource group go into effect */ resctrl_sched_in(); preempt_enable(); +out: kfree(callback); } @@ -725,6 +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 5adc6390ac3a..915686772f0e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -95,6 +95,7 @@ #include #include #include +#include #include #include "internal.h" #include "fd.h" @@ -3154,6 +3155,9 @@ 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), @@ -3554,6 +3558,9 @@ 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 */