Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 resource control updates from Ingo Molnar:
 "The main change in this tree is the extension of the resctrl procfs
  ABI with a new file that helps tooling to navigate from tasks back to
  resctrl groups: /proc/{pid}/cpu_resctrl_groups.

  Also fix static key usage for certain feature combinations and
  simplify the task exit resctrl case"

* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Add task resctrl information display
  x86/resctrl: Check monitoring static key in the MBM overflow handler
  x86/resctrl: Do not reconfigure exiting tasks
This commit is contained in:
Linus Torvalds 2020-01-28 12:00:29 -08:00
commit 4244057c3d
7 changed files with 119 additions and 2 deletions

View File

@ -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.

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@ -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

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@ -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;

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@ -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)
{

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@ -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

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@ -95,6 +95,7 @@
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
#include <linux/time_namespace.h>
#include <linux/resctrl.h>
#include <trace/events/oom.h>
#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),

14
include/linux/resctrl.h Normal file
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@ -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 */