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

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

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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.

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+86 −0
Original line number Diff line number Diff line
@@ -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)

{

fs/proc/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -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

fs/proc/base.c

+7 −0
Original line number Diff line number Diff line
@@ -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),

include/linux/resctrl.h

0 → 100644
+14 −0
Original line number Diff line number Diff line 
/* 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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