[PATCH v3 3/5] cgroup: selftests: Move cgroup_util into its own library

[James Houghton <jthoughton@google.com>]

KVM selftests will soon need to use some of the cgroup creation and
deletion functionality from cgroup_util.

Suggested-by: David Matlack <dmatlack@google.com>
Signed-off-by: James Houghton <jthoughton@google.com>
---
 tools/testing/selftests/cgroup/Makefile       | 21 ++++++++++---------
 .../selftests/cgroup/{ => lib}/cgroup_util.c  |  2 +-
 .../cgroup/{ => lib/include}/cgroup_util.h    |  4 ++--
 .../testing/selftests/cgroup/lib/libcgroup.mk | 19 +++++++++++++++++
 4 files changed, 33 insertions(+), 13 deletions(-)
 rename tools/testing/selftests/cgroup/{ => lib}/cgroup_util.c (99%)
 rename tools/testing/selftests/cgroup/{ => lib/include}/cgroup_util.h (99%)
 create mode 100644 tools/testing/selftests/cgroup/lib/libcgroup.mk

diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile
index 1b897152bab6e..e01584c2189ac 100644
--- a/tools/testing/selftests/cgroup/Makefile
+++ b/tools/testing/selftests/cgroup/Makefile
@@ -21,14 +21,15 @@ TEST_GEN_PROGS += test_zswap
 LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h
 
 include ../lib.mk
+include lib/libcgroup.mk
 
-$(OUTPUT)/test_core: cgroup_util.c
-$(OUTPUT)/test_cpu: cgroup_util.c
-$(OUTPUT)/test_cpuset: cgroup_util.c
-$(OUTPUT)/test_freezer: cgroup_util.c
-$(OUTPUT)/test_hugetlb_memcg: cgroup_util.c
-$(OUTPUT)/test_kill: cgroup_util.c
-$(OUTPUT)/test_kmem: cgroup_util.c
-$(OUTPUT)/test_memcontrol: cgroup_util.c
-$(OUTPUT)/test_pids: cgroup_util.c
-$(OUTPUT)/test_zswap: cgroup_util.c
+$(OUTPUT)/test_core: $(LIBCGROUP_O)
+$(OUTPUT)/test_cpu: $(LIBCGROUP_O)
+$(OUTPUT)/test_cpuset: $(LIBCGROUP_O)
+$(OUTPUT)/test_freezer: $(LIBCGROUP_O)
+$(OUTPUT)/test_hugetlb_memcg: $(LIBCGROUP_O)
+$(OUTPUT)/test_kill: $(LIBCGROUP_O)
+$(OUTPUT)/test_kmem: $(LIBCGROUP_O)
+$(OUTPUT)/test_memcontrol: $(LIBCGROUP_O)
+$(OUTPUT)/test_pids: $(LIBCGROUP_O)
+$(OUTPUT)/test_zswap: $(LIBCGROUP_O)
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/lib/cgroup_util.c
similarity index 99%
rename from tools/testing/selftests/cgroup/cgroup_util.c
rename to tools/testing/selftests/cgroup/lib/cgroup_util.c
index 1e2d46636a0ca..f047d8adaec65 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/lib/cgroup_util.c
@@ -17,7 +17,7 @@
 #include <unistd.h>
 
 #include "cgroup_util.h"
-#include "../clone3/clone3_selftests.h"
+#include "../../clone3/clone3_selftests.h"
 
 /* Returns read len on success, or -errno on failure. */
 static ssize_t read_text(const char *path, char *buf, size_t max_len)
diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h
similarity index 99%
rename from tools/testing/selftests/cgroup/cgroup_util.h
rename to tools/testing/selftests/cgroup/lib/include/cgroup_util.h
index 19b131ee77072..7a0441e5eb296 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h
@@ -2,9 +2,9 @@
 #include <stdbool.h>
 #include <stdlib.h>
 
-#include "../kselftest.h"
-
+#ifndef PAGE_SIZE
 #define PAGE_SIZE 4096
+#endif
 
 #define MB(x) (x << 20)
 
diff --git a/tools/testing/selftests/cgroup/lib/libcgroup.mk b/tools/testing/selftests/cgroup/lib/libcgroup.mk
new file mode 100644
index 0000000000000..7a73007204c39
--- /dev/null
+++ b/tools/testing/selftests/cgroup/lib/libcgroup.mk
@@ -0,0 +1,19 @@
+CGROUP_DIR := $(selfdir)/cgroup
+
+LIBCGROUP_C := lib/cgroup_util.c
+
+LIBCGROUP_O := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBCGROUP_C))
+
+LIBCGROUP_O_DIRS := $(shell dirname $(LIBCGROUP_O) | uniq)
+
+CFLAGS += -I$(CGROUP_DIR)/lib/include
+
+EXTRA_HDRS := $(selfdir)/clone3/clone3_selftests.h
+
+$(LIBCGROUP_O_DIRS):
+	mkdir -p $@
+
+$(LIBCGROUP_O): $(OUTPUT)/%.o : $(CGROUP_DIR)/%.c $(EXTRA_HDRS) $(LIBCGROUP_O_DIRS)
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+
+EXTRA_CLEAN += $(LIBCGROUP_O)
-- 
2.49.0.604.gff1f9ca942-goog