controllers/pids: Add new testcases

Created new testcases to test the pids controller which is used to stop any new tasks from being fork()'d after a certain limit is reached.

Signed-off-by Cedric Hnyda <[email protected]>

index 0000000..6500363

testcases/kernel/controllers/pids/Makefile new file +6 -0

@@ -0,0 +1,28 @@
+#
+#    Copyright (C) 2015, SUSE
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or

testcases/kernel/controllers/pids/pids_task2.c line 58

Quoted 3 lines

testcases/kernel/controllers/pids/pids_task2.c new file +3 -0

+
+    while (1) {
+    }

Is it necessary to add a busy loop to completely load CPU? If we only wait, I would add a sleep, something like

while (1)

     usleep(10);

Quoted 6 lines

Is it necessary to add a busy loop to completely load CPU? If we only wait, I would add a sleep, something like

while (1)

     usleep(10);

You are absolutely right, it is not needed at all to completely load CPU. Maybe it would also be better to use sleep rather than usleep.

testcases/kernel/controllers/pids/.gitignore new file +37 -0

+cleanup()
+{
+	killall -9 pids_task2 > /dev/null
+
+	tst_resm TINFO "removing created directories"
+	rmdir $testpath
+	if [ "$mounted" -ne "1" ]; then
+		tst_resm TINFO "Umounting pids"
+		umount $mount_point
+		rmdir $mount_point
+	fi
+}
+
+setup()
+{
+	tst_require_root
+
+	exist=`grep -w pids /proc/cgroups | cut -f1`;
+	if [ "$exist" = "" ]; then
+		tst_brkm TCONF NULL "pids not supported"
+	fi
+
+	mount_point=`grep -w pids /proc/mounts | cut -f 2 | cut -d " " -f2`
+
+	if [ "$mount_point" = "" ]; then
+		mounted=0
+		mount_point=/dev/cgroup
+	fi
+
+	TST_CLEANUP=cleanup
+
+	testpath=$mount_point/ltp_$TCID
+
+	if [ "$mounted" -eq "0" ]; then
+		ROD mkdir -p $mount_point
+		ROD mount -t cgroup -o pids none $mount_point
+	fi

testcases/kernel/controllers/pids/.gitignore new file +16 -0

+	# should return 0 because there is no limit
+	pids_task "$testpath/tasks"
+	ret=$?
+
+	killall -9 pids_task2
+
+	if [ "$ret" -eq "2" ]; then
+		tst_resm TFAIL "fork failed unexpectedly"
+	elif [ "$ret" -eq "0" ]; then
+		tst_resm TPASS "fork didn't fail"
+	else
+		tst_resm TBROK "pids_task failed"
+	fi
+}
+
+case2()

testcases/kernel/controllers/pids/.gitignore new file +17 -0

+	# should return 2 because the limit of pids is reached
+	pids_task "$testpath/tasks"
+	ret=$?
+
+	killall -9 pids_task2
+
+	if [ "$ret" -eq "2" ]; then
+		tst_resm TPASS "fork failed as expected"
+	elif [ "$ret" -eq "0" ]; then
+		tst_resm TFAIL "fork didn't fail despite the limit"
+	else
+		tst_resm TBROK "pids_task failed"
+	fi
+}
+
+case3()
+{

testcases/kernel/controllers/pids/.gitignore new file +20 -0

+	pids_task "$testpath/tasks"
+	ret=$?
+
+	killall -9 pids_task2
+
+	if [ "$ret" -eq "2" ]; then
+		tst_resm TFAIL "fork failed unexpectedly"
+	elif [ "$ret" -eq "0" ]; then
+		tst_resm TPASS "fork worked as expected"
+	else
+		tst_resm TBROK "pids_task failed"
+	fi
+}
+
+case4()
+{
+	tst_resm TINFO "limit the number of avalaible pid to 0"
+	ROD echo 0 > $testpath/pids.max
+
+	for i in `seq 1 $max`; do

testcases/kernel/controllers/pids/.gitignore new file +31 -0

+	killall -9 pids_task2
+
+	if [ "$cnt" -ne "$max" ]; then
+		cnt=$((max - cnt))
+		tst_resm TFAIL "$cnt process were not attached successfully"
+	else
+		tst_resm TPASS "all process were attached"
+	fi
+}
+
+case5()
+{
+	tst_resm TINFO "try to limit the number of avalaible pid to -1"
+	echo -1 > $testpath/pids.max
+
+	if [ "$?" -eq "0" ]; then
+		tst_resm TFAIL "managed to set the limit to -1"
+	else
+		tst_resm TPASS "didn't manage to set the limit to -1"
+	fi
+}
+
+setup
+
+if [ "$#" -ne "2" ]; then
+	usage
+else
+	case$caseno
+fi
+
+tst_exit

testcases/kernel/controllers/pids/pids_task.c new file +53 -0

new file mode 100644
index 0000000..a470ccf
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2015 Cedric Hnyda <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+* Description:
+* Write the current process in argv[1]
+* and returns:
+*	-> 2 if fork fails with EAGAIN,
+*	-> 1 if there is another problem
+*	-> 0 if everything worked
+*/
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+	FILE *f;
+	int newpid;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s /cgroup/.../tasks\n", argv[0]);
+		return 1;
+	}
+
+	f = fopen(argv[1], "a");
+	if (!f) {
+		perror("fopen failed");
+		return 1;
+	}
+
+	fprintf(f, "%i\n", getpid());
+	fclose(f);

testcases/kernel/controllers/pids/pids_task.c new file +32 -0

+/*
+* Description:
+* Write the current process in argv[1],
+* return 1 if there is a problem in attaching the process,
+* otherwise do an infinite loop
+*/
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv)
+{
+	FILE *f;
+	int i;
+
+	i = 0;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s /cgroup/.../tasks\n", argv[0]);
+		return 1;
+	}
+
+	f = fopen(argv[1], "a");
+	if (!f) {
+		perror("fopen failed");
+		return 1;
+	}
+