systemd and fs2 ignore update --cpu-period if cpu-quota was/is not set #2464
Description
systemd/v1, systemd/v2 and fs2 cgroup drivers ignore the CPU period during start/run, if CPU quota is not set.
Only the fs (v1) driver sets the period, working as expected.
Repro for systemd:
# make sure no quota/period set in config.json
runc --systemd-cgroup run -d --console-socket $CONSOLE_SOCKET test_update
# update the quota alone, no old values were set
runc --systemd-cgroup update --cpu-period 30000 test_update
# check the value for v1:
cat /sys/fs/cgroup/$CGPATH/cpu.cfs_period_us
# check the value for v2:
cat /sys/fs/cgroup/$CGPATH/cpu.max(same repro for fs2 driver, modulo --systemd-cgroup).
Expected value for period (second value in cpu.max) is the one set, i.e. 30000. Actual value is 100000.