The test robot reported two different problems when running the test_cpuset_prs.sh test. # ./test_cpuset_prs.sh: line 106: echo: write error: Input/output error # : # Effective cpus changed to 0-1,4-7 after test 4! The write error is caused by writing to /dev/console. It looks like some systems may not have /dev/console configured or in a writeable state. Fix this by checking the existence of /dev/console before attempting to write it. After the completion of each test run, the script will check if the cpuset state is reset back to the original state. That usually takes a while to happen. The test script inserts some artificial delay to make sure that the reset has completed. The current setting is about 80ms. That may not be enough in some cases especially if the test system is slow. Double it to 160ms to minimize the chance of this type of failure. Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> Closes: https://lore.kernel.org/oe-lkp/202406141712.dbbaa8fd-oliver.sang@xxxxxxxxx Signed-off-by: Waiman Long <longman@xxxxxxxxxx> --- .../selftests/cgroup/test_cpuset_prs.sh | 20 +++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index b5eb1be2248c..96bf2b5c5eb6 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -28,6 +28,14 @@ CPULIST=$(cat $CGROUP2/cpuset.cpus.effective) NR_CPUS=$(lscpu | grep "^CPU(s):" | sed -e "s/.*:[[:space:]]*//") [[ $NR_CPUS -lt 8 ]] && skip_test "Test needs at least 8 cpus available!" +# Check to see if /dev/console exists and is writable +if [[ -c /dev/console && -w /dev/console ]] +then + CONSOLE=/dev/console +else + CONSOLE=/dev/null +fi + # Set verbose flag and delay factor PROG=$1 VERBOSE=0 @@ -103,8 +111,8 @@ console_msg() { MSG=$1 echo "$MSG" - echo "" > /dev/console - echo "$MSG" > /dev/console + echo "" > $CONSOLE + echo "$MSG" > $CONSOLE pause 0.01 } @@ -694,9 +702,9 @@ null_isolcpus_check() [[ $VERBOSE -gt 0 ]] || return 0 # Retry a few times before printing error RETRY=0 - while [[ $RETRY -lt 5 ]] + while [[ $RETRY -lt 8 ]] do - pause 0.01 + pause 0.02 check_isolcpus "." [[ $? -eq 0 ]] && return 0 ((RETRY++)) @@ -726,7 +734,7 @@ run_state_test() while [[ $I -lt $CNT ]] do - echo "Running test $I ..." > /dev/console + echo "Running test $I ..." > $CONSOLE [[ $VERBOSE -gt 1 ]] && { echo "" eval echo \${$TEST[$I]} @@ -783,7 +791,7 @@ run_state_test() while [[ $NEWLIST != $CPULIST && $RETRY -lt 8 ]] do # Wait a bit longer & recheck a few times - pause 0.01 + pause 0.02 ((RETRY++)) NEWLIST=$(cat cpuset.cpus.effective) done -- 2.39.3
