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, 24 insertions, 0 deletions

diff --git a/fs/proc/cmdline.c b/fs/proc/cmdline.c
new file mode 100644
index 000000000..a6f761219
--- /dev/null
+++ b/fs/proc/cmdline.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "internal.h"
+
+static int cmdline_proc_show(struct seq_file *m, void *v)
+{
+	seq_puts(m, saved_command_line);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static int __init proc_cmdline_init(void)
+{
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("cmdline", 0, NULL, cmdline_proc_show);
+	pde_make_permanent(pde);
+	pde->size = saved_command_line_len + 1;
+	return 0;
+}
+fs_initcall(proc_cmdline_init);