On 12/4/18 6:47 PM, Josef Bacik wrote:
> This is a test to verify io.latency is working properly. It does this
> by first running a fio job by itself to figure out how fast it runs.
> Then we calculate some thresholds, set up 2 cgroups, a fast and a slow
> cgroup, and then run the same job in both groups simultaneously. We
> should see the slow group get throttled until the first cgroup is able
> to finish, and then the slow cgroup will be allowed to finish.
>
Hi,
two small typos below.
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
> tests/block/025 | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/block/025.out | 1 +
> 2 files changed, 134 insertions(+)
> create mode 100644 tests/block/025
> create mode 100644 tests/block/025.out
>
> diff --git a/tests/block/025 b/tests/block/025
> new file mode 100644
> index 000000000000..88ce7cca944e
> --- /dev/null
> +++ b/tests/block/025
> @@ -0,0 +1,133 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +#
> +# Test io.latency to make sure it's protecting the higher priority group
> +# properly.
> +
> +. tests/block/rc
> +
> +DESCRIPTION="test the io.latency interface to make sure it's working right"
> +
> +requires() {
> + _have_cgroup2_controller_file io io.latency && _have_fio && \
> + _have_program python
> +}
> +
> +_fio_results_key() {
> + _job=$1
> + _key=$2
> + _resultfile=$3
> +
> + python src/fio-key-value.py -k $_key -j $_job $_resultfile
> +}
> +
> +test_device() {
> + local fio_config_single fio_config_double fio_results fio_args qd
> +
> + fio_config_single=${TMPDIR}/single.fio
> + fio_config_double=${TMPDIR}/double.fio
> + fio_results=${TMPDIR}/025.json
> + fio_args="--output-format=json --output=${fio_results}"
> + qd=$(cat ${TEST_DEV_SYSFS}/queue/nr_requests)
> +
> + cat << EOF > "${fio_config_single}"
> + [fast]
> + filename=${TEST_DEV}
> + direct=1
> + allrandrepeat=1
> + readwrite=randrw
> + size=4G
> + ioengine=libaio
> + iodepth=${qd}
> + fallocate=none
> + randseed=12345
> +EOF
> +
> + cat << EOF > "${fio_config_double}"
> + [global]
> + filename=${TEST_DEV}
> + direct=1
> + allrandrepeat=1
> + readwrite=randrw
> + size=4G
> + ioengine=libaio
> + iodepth=${qd}
> + fallocate=none
> + randseed=12345
> +
> + [fast]
> + cgroup=blktests/fast
> +
> + [slow]
> + cgroup=blktests/slow
> +EOF
> + # We run the test once so we have an idea of how fast this workload will
> + # go with nobody else doing IO on the device.
> + if ! fio ${fio_args} ${fio_config_single}; then
> + echo "fio exited with status $?"
> + return 1
> + fi
> +
> + _time_taken=$(_fio_results_key fast job_runtime ${fio_results})
> + if [ "${_time_taken}" = "" ]; then
> + echo "fio doesn't report job_runtime"
> + return 1
> + fi
> +
> + echo "normal time taken ${_time_taken}" >> $FULL
> +
> + # There's no way to predict how the two workloads are going to affect
> + # each other, so we weant to set thresholds to something reasonable so
> + # we can verify io.latency is doing something. This means we set 15%
> + # for the fast cgroup, just to give us enough wiggle room as throttling
> + # doesn't happen immediately. But if we have a super fast disk we could
> + # run both groups really fast and make it under our fast threshold, so
> + # we need to set a threshold for the slow group at 50%. We assume that
> + # if it was faster than 50% of the fast threshold then we probably
> + # didn't throttle and we can assume io.latency is broken.
> + _fast_thresh=$((${_time_taken} + ${_time_taken} * 15 / 100))
> + _slow_thresh=$((${_time_taken} + ${_time_taken} * 50 / 100))
> + echo "fast threshold time is ${_fast_thresh}" >> $FULL
> + echo "slow threshold time is ${_slow_thresh}" >> $FULL
> +
> + # Create teh cgroup files
Typo, "the". ^
> + _dir=$(_cgroup2_base_dir)/blktests
> + echo "+io" > ${_dir}/cgroup.subtree_control
> + mkdir ${_dir}/fast
> + mkdir ${_dir}/slow
> +
> + # We set teh target to 1usec because we could have a fast device that is
Also here, "the". ^
> + # capable of remarkable IO latencies that would skew the test. It needs
> + # to be low enough that we do actually throttle the slow group,
> + # otherwise the test will fail when there's nothing wrong.
> + _major=$((0x$(stat -c "%t" ${TEST_DEV})))
> + _minor=$((0x$(stat -c "%T" ${TEST_DEV})))
> + echo "${_major}:${_minor} is our device" >> $FULL
> + if ! echo "${_major}:${_minor} target=1" > ${_dir}/fast/io.latency; then
> + echo "Failed to set our latency target"
> + return 1
> + fi
> +
> + if ! fio ${fio_args} ${fio_config_double}; then
> + echo "fio exited with status $?"
> + return 1
> + fi
> +
> + _fast_time=$(_fio_results_key fast job_runtime ${fio_results})
> + echo "Fast time ${_fast_time}" >> $FULL
> + _slow_time=$(_fio_results_key slow job_runtime ${fio_results})
> + echo "Slow time ${_slow_time}" >> $FULL
> +
There is a trailing whitespace in the above line.
> + if [ ${_fast_thresh} -lt ${_fast_time} ]; then
> + echo "Too much of a performance drop for the protected workload"
> + return 1
> + fi
> +
> + if [ ${_slow_thresh} -gt ${_slow_time} ]; then
> + echo "The slow group does not appear to have been throttled"
> + return 1
> + fi
> +
> + echo "Silence is golden"
> + return 0
> +}
> diff --git a/tests/block/025.out b/tests/block/025.out
> new file mode 100644
> index 000000000000..c19ff631b9b5
> --- /dev/null
> +++ b/tests/block/025.out
> @@ -0,0 +1 @@
> +Silence is golden
>
Thank you,
Federico
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