From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 31 Mar 2021 17:16:16 +0000 (+0000)
Subject: cgroups: Add function to set nice level
X-Git-Tag: 0.9.28~1285^2~449
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=820c32c74e20017e5eaf3507f14e3a7523fa998c;p=pakfire.git

cgroups: Add function to set nice level

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/cgroup.c b/src/libpakfire/cgroup.c
index c57e68a58..4a582b549 100644
--- a/src/libpakfire/cgroup.c
+++ b/src/libpakfire/cgroup.c
@@ -183,7 +183,7 @@ static FILE* pakfire_cgroup_fopen(Pakfire pakfire,
 static int pakfire_cgroup_fprintf(Pakfire pakfire,
 		const char* group, const char* file, const char* format, ...) {
 	char buffer[64];
-	size_t length;
+	ssize_t length;
 	int r;
 	va_list args;
 
@@ -200,6 +200,10 @@ static int pakfire_cgroup_fprintf(Pakfire pakfire,
 	// if the operation was successful.
 	r = write(fileno(f), buffer, length);
 
+	// Return zero if everything was written correctly
+	if (r == length)
+		r = 0;
+
 	fclose(f);
 
 	return r;
@@ -490,3 +494,16 @@ int pakfire_cgroup_cpustat(Pakfire pakfire, const char* group,
 
 	return 0;
 }
+
+int pakfire_cgroup_set_nice(Pakfire pakfire, const char* group, int level) {
+	DEBUG(pakfire, "Setting nice level of cgroup %s to %d\n", group, level);
+
+	int r = pakfire_cgroup_fprintf(pakfire, group, "cpu.weight.nice", "%d", level);
+	if (r) {
+		ERROR(pakfire, "Could not change nice level of cgroup %s: %s\n",
+			group, strerror(errno));
+		return r;
+	}
+
+	return 0;
+}
diff --git a/src/libpakfire/include/pakfire/cgroup.h b/src/libpakfire/include/pakfire/cgroup.h
index 3ac6d4418..df8fb4d2d 100644
--- a/src/libpakfire/include/pakfire/cgroup.h
+++ b/src/libpakfire/include/pakfire/cgroup.h
@@ -52,6 +52,8 @@ struct pakfire_cgroup_cpustat {
 int pakfire_cgroup_cpustat(Pakfire pakfire, const char* group,
 		struct pakfire_cgroup_cpustat* st);
 
+int pakfire_cgroup_set_nice(Pakfire pakfire, const char* group, int level);
+
 #endif
 
 #endif /* PAKFIRE_CGROUP_H */
diff --git a/tests/libpakfire/cgroup.c b/tests/libpakfire/cgroup.c
index 508614a3e..95df51bbc 100644
--- a/tests/libpakfire/cgroup.c
+++ b/tests/libpakfire/cgroup.c
@@ -163,6 +163,23 @@ static int test_cpustat(const struct test* t) {
 	);
 }
 
+static int test_nice(const struct test* t) {
+	ASSERT_SUCCESS(
+		pakfire_cgroup_create(t->pakfire, "pakfire/test")
+	);
+
+	// Set nice level
+	ASSERT_SUCCESS(
+		pakfire_cgroup_set_nice(t->pakfire, "pakfire/test", 5)
+	);
+
+	ASSERT_SUCCESS(
+		pakfire_cgroup_destroy(t->pakfire, "pakfire/test")
+	);
+
+	return EXIT_SUCCESS;
+}
+
 static int test_random_name(const struct test* t) {
 	char name1[] = "pakfire/execute-XXXXXX";
 	char name2[] = "pakfire/execute-XXXXXX";
@@ -182,6 +199,7 @@ int main(int argc, char** argv) {
 	testsuite_add_test(test_killall);
 	testsuite_add_test(test_cpustat);
 	testsuite_add_test(test_random_name);
+	testsuite_add_test(test_nice);
 
 	return testsuite_run();
 }