Monitoring tools that want to find out which resctrl CTRL
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}/resctrl to provide this
information.
For example:
cat /proc/1193/resctrl
CTRL_MON:/ctrl_grp0
MON:/ctrl_grp0/mon_groups/mon_grp0
If the resctrl filesystem has not been mounted,
reading /proc/{pid}/resctrl returns an error:
cat: /proc/1193/resctrl: No such device
Tested-by: Jinshi Chen <jinshi.chen@xxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
arch/x86/include/asm/resctrl_sched.h | 4 +++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++
fs/proc/base.c | 9 +++++
3 files changed, 59 insertions(+)
diff --git a/arch/x86/include/asm/resctrl_sched.h b/arch/x86/include/asm/resctrl_sched.h
index f6b7fe2833cc..bba362e0e00f 100644
--- a/arch/x86/include/asm/resctrl_sched.h
+++ b/arch/x86/include/asm/resctrl_sched.h
@@ -5,6 +5,7 @@
#ifdef CONFIG_X86_CPU_RESCTRL
#include <linux/sched.h>
+#include <linux/proc_fs.h>
#include <linux/jump_label.h>
#define IA32_PQR_ASSOC 0x0c8f
@@ -84,6 +85,9 @@ static inline void resctrl_sched_in(void)
__resctrl_sched_in();
}
+int proc_resctrl_show(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *tsk);
+
#else
static inline void resctrl_sched_in(void) {}
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a46dee8e78db..2317174174e9 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -727,6 +727,52 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
return ret;
}
+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);
+
+ /* Make sure resctrl has been mounted. */
+ if (!static_branch_unlikely(&rdt_enable_key)) {
+ ret = -ENODEV;
+ 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) {
+ seq_printf(s, "CTRL_MON:/%s\n", rdtg->kn->name);
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (tsk->rmid != crg->mon.rmid)
+ continue;
+ seq_printf(s, "MON:%s%s/mon_groups/%s\n",
+ rdtg == &rdtgroup_default ? "" : "/",
+ rdtg->kn->name, crg->kn->name);
+ goto unlock;
+ }
+ goto unlock;
+ }
+ }
+ ret = -ENOENT;
+unlock:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return ret;
+}
+
static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
struct seq_file *seq, void *v)
{
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ebea9501afb8..d8a61db78db5 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -95,6 +95,9 @@
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
#include <trace/events/oom.h>
+#ifdef CONFIG_X86_CPU_RESCTRL
+#include <asm/resctrl_sched.h>
+#endif
#include "internal.h"
#include "fd.h"
@@ -3060,6 +3063,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#endif
#ifdef CONFIG_CGROUPS
ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+#ifdef CONFIG_X86_CPU_RESCTRL
+ ONE("resctrl", 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 +3466,9 @@ static const struct pid_entry tid_base_stuff[] = {
#endif
#ifdef CONFIG_CGROUPS
ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+#ifdef CONFIG_X86_CPU_RESCTRL
+ ONE("resctrl", 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),
--
2.17.1
