From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Tue, 10 Jan 2023 14:13:43 +0000 (+0000)
Subject: tools/cgclassify: add support for default systemd delegation slice/scope
X-Git-Tag: v3.1.0~204
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08ee9e36dee97bd32b0e648090b2e7570a1935fb;p=thirdparty%2Flibcgroup.git

tools/cgclassify: add support for default systemd delegation slice/scope

Enhance the cgclassify tool to support default systemd delegation
slice/scope, if set in the cgconfig.conf's systemd setting.  Parse the
configuration file and read the systemd::delegate setting, if
any, and set it as the default systemd slice/scope in
systemd_default_cgroup. Setting it appends the slice/scope
name to the constructed default cgroup mount path.

When the user passes the relative cgroup name, its appends to the
sub-tree (delegated slice/scope) by default and if the user wishes to
create a cgroup in another subtree or cgroup root hierarchy, they need
to use the absolute path. For example:

                      cgroup_root
                     /          \
                    /            \
             systemd.slice*      cgrp1
                    |
             systemd.scope
                    |
                cgrp-d1

* default system delegation slice/scope - read from cgconfig.conf
$ sudo cgclassify -g cpu:cgrp-d1 1379 (pid)

will create the cgroup under the cpu controller hirearchy
cgroup_root:systemd_default_cgroup:cgrp-d1

and for creating a cgroup cgrp1, the user can use:
$ sudo cgclassify -g cpu:/cgrp1 1379 (pid)

or use the newly introduced -b switch to ignore the systemd slice/scope:
$ sudo cgclassify -b -g cpu:cgrp1 1379 (pid)

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

diff --git a/src/tools/cgclassify.c b/src/tools/cgclassify.c
index 147b9dbf..f9f8aa88 100644
--- a/src/tools/cgclassify.c
+++ b/src/tools/cgclassify.c
@@ -41,6 +41,9 @@ static void usage(int status, const char *program_name)
 	info("  --cancel-sticky		cgred daemon change pidlist and children tasks\n");
 	info("  --sticky			cgred daemon does not change ");
 	info("pidlist and children tasks\n");
+#ifdef WITH_SYSTEMD
+	info("  -b				Ignore default systemd delegate hierarchy\n");
+#endif
 }
 
 /*
@@ -113,6 +116,7 @@ static struct option longopts[] = {
 int main(int argc, char *argv[])
 {
 	struct cgroup_group_spec *cgroup_list[CG_HIER_MAX];
+	int ignore_default_systemd_delegate_slice = 0;
 	int ret = 0, i, exit_code = 0;
 	int cg_specified = 0;
 	int flag = 0;
@@ -126,8 +130,16 @@ int main(int argc, char *argv[])
 	}
 
 	memset(cgroup_list, 0, sizeof(cgroup_list));
+#ifdef WITH_SYSTEMD
+	while ((c = getopt_long(argc, argv, "+g:shb", longopts, NULL)) > 0) {
+		switch (c) {
+		case 'b':
+			ignore_default_systemd_delegate_slice = 1;
+			break;
+#else
 	while ((c = getopt_long(argc, argv, "+g:sh", longopts, NULL)) > 0) {
 		switch (c) {
+#endif
 		case 'h':
 			usage(0, argv[0]);
 			exit(0);
@@ -160,6 +172,10 @@ int main(int argc, char *argv[])
 		return ret;
 	}
 
+	/* this is false always for disable-systemd */
+	if (!ignore_default_systemd_delegate_slice)
+		cgroup_set_default_systemd_cgroup();
+
 	for (i = optind; i < argc; i++) {
 		pid = (pid_t) strtol(argv[i], &endptr, 10);
 		if (endptr[0] != '\0') {