iocost_monitor: exit successfully if interval is zero
This is to help external tools to decide whether iocost_monitor has all its
requirements met or not based on the exit status of an -i0 run.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/tools/cgroup/iocost_monitor.py b/tools/cgroup/iocost_monitor.py
index 7427a5e..eb2363b 100644
--- a/tools/cgroup/iocost_monitor.py
+++ b/tools/cgroup/iocost_monitor.py
@@ -28,7 +28,8 @@
parser.add_argument('--cgroup', action='append', metavar='REGEX',
help='Regex for target cgroups, ')
parser.add_argument('--interval', '-i', metavar='SECONDS', type=float, default=1,
- help='Monitoring interval in seconds')
+ help='Monitoring interval in seconds (0 exits immediately '
+ 'after checking requirements)')
parser.add_argument('--json', action='store_true',
help='Output in json')
args = parser.parse_args()
@@ -243,6 +244,9 @@
if ioc is None:
err(f'Could not find ioc for {devname}');
+if interval == 0:
+ sys.exit(0)
+
# Keep printing
while True:
now = time.time()
