docs: cgroup-v2: fix misc.events key format descriptiongrafted

In misc cgroup, misc.events does not output a simple "max" key. Instead,
each registered misc resource outputs a separate key suffixed with ".max"
(i.e., "<res>.max").
Update the documentation to clarify that the entry key is "<res>.max".

Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/fs/proc/cpuinfo.c b/fs/proc/cpuinfo.c
new file mode 100644
index 000000000..f38bda5b8
--- /dev/null
+++ b/fs/proc/cpuinfo.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/cpufreq.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+extern const struct seq_operations cpuinfo_op;
+
+static int cpuinfo_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &cpuinfo_op);
+}
+
+static const struct proc_ops cpuinfo_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
+	.proc_open	= cpuinfo_open,
+	.proc_read_iter	= seq_read_iter,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+};
+
+static int __init proc_cpuinfo_init(void)
+{
+	proc_create("cpuinfo", 0, NULL, &cpuinfo_proc_ops);
+	return 0;
+}
+fs_initcall(proc_cpuinfo_init);