Commit e79f15a4 authored by Chen Yu's avatar Chen Yu Committed by Borislav Petkov

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: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Tested-by: default avatarJinshi Chen <jinshi.chen@intel.com>
Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com
parent 536a0d8e
......@@ -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.
......
......@@ -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)
{
......
......@@ -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
......@@ -94,6 +94,7 @@
#include <linux/sched/debug.h>
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
#include <linux/resctrl.h>
#include <trace/events/oom.h>
#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),
......
/* 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 */
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