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authorChen Yu <yu.c.chen@intel.com>2020-01-15 17:28:51 +0800
committerBorislav Petkov <bp@suse.de>2020-01-20 16:19:10 +0100
commite79f15a4598c1f3f3f7f3319ca308c63c91fdaf2 (patch)
treeddd82880c6aa0d623de777e89946d4d96d07884a /arch/x86/kernel/cpu/resctrl
parent536a0d8e79fb928f2735db37dda95682b6754f9a (diff)
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: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Jinshi Chen <jinshi.chen@intel.com> Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com
Diffstat (limited to 'arch/x86/kernel/cpu/resctrl')
-rw-r--r--arch/x86/kernel/cpu/resctrl/rdtgroup.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 205925d802d8..5b3ba83013b5 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -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)
{