From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Mon, 10 Oct 2022 15:52:14 +0000 (+0530)
Subject: tools/cgget: add support to print cgroup setup
X-Git-Tag: v3.1.0~284
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ca42f62cdf5e4b0c3bb3920ab5aa52476cbe8096;p=thirdparty%2Flibcgroup.git

tools/cgget: add support to print cgroup setup

Add a new switch (-m), that will print the current cgroup mode the
system/VM is booted it.  It uses the API, cgroup_setup_mode() that
returns one of the modes (Legacy/Unified/Hybrid) the system is
booted with.

$ cgget -m
Legacy Mode (Cgroup v1 only).

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
---

diff --git a/src/tools/cgget.c b/src/tools/cgget.c
index bf3e0aad..54528846 100644
--- a/src/tools/cgget.c
+++ b/src/tools/cgget.c
@@ -17,6 +17,8 @@
 
 #define LL_MAX			100
 
+static int find_cgroup_mount_type(void);
+
 static const struct option long_options[] = {
 	{"variable",	required_argument, NULL, 'r'},
 	{"help",	      no_argument, NULL, 'h'},
@@ -41,6 +43,7 @@ static void usage(int status, const char *program_name)
 	info("  -r, --variable <name>		Define parameter to display\n");
 	info("  -v, --values-only		Print only values, not ");
 	info("parameter names\n");
+	info("  -m				Display the cgroup mode\n");
 }
 
 static int get_controller_from_name(const char * const name, char **controller)
@@ -395,7 +398,7 @@ static int parse_opts(int argc, char *argv[], struct cgroup **cg_list[], int * c
 	int c;
 
 	/* Parse arguments. */
-	while ((c = getopt_long(argc, argv, "r:hnvg:a", long_options, NULL)) > 0) {
+	while ((c = getopt_long(argc, argv, "r:hnvg:am", long_options, NULL)) > 0) {
 		switch (c) {
 		case 'h':
 			usage(0, argv[0]);
@@ -434,6 +437,11 @@ static int parse_opts(int argc, char *argv[], struct cgroup **cg_list[], int * c
 			if (ret)
 				goto err;
 			break;
+		case 'm':
+			ret = find_cgroup_mount_type();
+			if (ret)
+				goto err;
+			break;
 		default:
 			usage(1, argv[0]);
 			exit(EXIT_BADARGS);
@@ -750,3 +758,28 @@ err:
 
 	return ret;
 }
+
+static int find_cgroup_mount_type(void)
+{
+	enum cg_setup_mode_t setup_mode;
+	int ret = 0;
+
+	setup_mode = cgroup_setup_mode();
+	switch(setup_mode) {
+	case CGROUP_MODE_LEGACY:
+		info("Legacy Mode (Cgroup v1 only).\n");
+		break;
+	case CGROUP_MODE_HYBRID:
+		info("Hybrid mode (Cgroup v1/v2).\n");
+		break;
+	case CGROUP_MODE_UNIFIED:
+		info("Unified Mode (Cgroup v2 only).\n");
+		break;
+	default:
+		err("Unable to determine the Cgroup setup mode.\n");
+		ret = 1;
+		break;
+	}
+
+	return ret;
+}