Hi Suzuki, On Wed, Aug 12, 2020 at 05:59:55PM +0100, Suzuki Kuruppassery Poulose wrote: > Hi Leo, > > On 08/06/2020 08:02 AM, Leo Yan wrote: > > We need a simple method to test Perf with Arm CoreSight drivers, this > > could be used for smoke testing when new patch is coming for perf or > > CoreSight drivers, and we also can use the test to confirm if the > > CoreSight has been enabled successfully on new platforms. > > > > This patch introduces the shell script test_arm_coresight.sh which is > > under the 'pert test' framework. This script provides three testing > > scenarios: > > Thank you for this testcase. It is a very good tool for people > check their system for CoreSight driver functionality.
My pleasure! This patch is except for ourselves testing, one main purpose is to integrate Perf testing with LKFT [1] for Arm related PMU events. [1] https://lkft.linaro.org/tests/ > > Test scenario 1: traverse all possible paths between source and sink > > > > For traversing possible paths, simply to say, the testing rationale > > is source oriented testing, it traverses every source (now only refers > > to ETM device) and test its all possible sinks. To search the complete > > paths from one specific source to its sinks, this patch relies on the > > sysfs '/sys/bus/coresight/devices/devX/out:Y' for depth-first search > > (DFS) for iteration connected device nodes, if the output device is > > detected as one of ETR, ETF, or ETB types then it will test trace data > > Please see my suggestion below, to use "enable_sink" as an indicator > for a sink device. > > > recording and decoding for this PMU device. > > > > The script runs three output testings for every trace data: > > - Test branch samples dumping with 'perf script' command; > > - Test branch samples reporting with 'perf report' command; > > - Use option '--itrace=i1000i' to insert synthesized instructions events > > and the script will check if perf can output the percentage value > > successfully based on the instruction samples. > > > > Test scenario 2: CPU wide mode test > > > For CPU wide mode testing, it passes option '-a' to perf tool to enable > > tracing on all CPUs, so it's hard to say which program will be traced. > > Isn't this system-wide, when you trace all CPUs ? In CPU wide mode, > you specify a list of CPUs (-C ?). I always get confused here. Agree, it is system-wide tracing. Will fix. > > But perf tool itself contributes much overload in this case, so it will > > parse trace data and check if process 'perf' can be detected or not. > > > > diff --git a/tools/perf/tests/shell/test_arm_coresight.sh > > b/tools/perf/tests/shell/test_arm_coresight.sh > > new file mode 100755 > > index 000000000000..73b973bada26 > > --- /dev/null > > +++ b/tools/perf/tests/shell/test_arm_coresight.sh > > @@ -0,0 +1,172 @@ > > +#!/bin/sh > > +# Check Arm CoreSight trace data recording and branch samples > > + > > +# Uses the 'perf record' to record trace data with Arm CoreSight sinks; > > +# then verify if there have any branch samples and instruction samples > > +# are generated by CoreSight with 'perf script' and 'perf report' > > +# commands. > > + > > +# SPDX-License-Identifier: GPL-2.0 > > +# Leo Yan <leo....@linaro.org>, 2020 > > + > > +perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX) > > +file=$(mktemp /tmp/temporary_file.XXXXX) > > + > > +skip_if_no_cs_etm_event() { > > + perf list | grep -q 'cs_etm//' && return 0 > > + > > + # cs_etm event doesn't exist > > + return 2 > > +} > > + > > +skip_if_no_cs_etm_event || exit 2 > > + > > +record_touch_file() { > > + echo "Recording trace (only user mode) with path: CPU$2 => $1" > > + perf record -o ${perfdata} -e cs_etm/@$1/u --per-thread \ > > + -- taskset -c $2 touch $file > > +} > > + > > +perf_script_branch_samples() { > > + echo "Looking at perf.data file for dumping branch samples:" > > + > > + # Below is an example of the branch samples dumping: > > + # touch 6512 1 branches:u: ffffb220824c > > strcmp+0xc (/lib/aarch64-linux-gnu/ld-2.27.so) > > + # touch 6512 1 branches:u: ffffb22082e0 > > strcmp+0xa0 (/lib/aarch64-linux-gnu/ld-2.27.so) > > + # touch 6512 1 branches:u: ffffb2208320 > > strcmp+0xe0 (/lib/aarch64-linux-gnu/ld-2.27.so) > > + perf script -F,-time -i ${perfdata} | \ > > + egrep " +$1 +[0-9]+ .* +branches:([u|k]:)? +" > > +} > > + > > +perf_report_branch_samples() { > > + echo "Looking at perf.data file for reporting branch samples:" > > + > > + # Below is an example of the branch samples reporting: > > + # 73.04% 73.04% touch libc-2.27.so [.] _dl_addr > > + # 7.71% 7.71% touch libc-2.27.so [.] getenv > > + # 2.59% 2.59% touch ld-2.27.so [.] strcmp > > + perf report --stdio -i ${perfdata} | \ > > + egrep " +[0-9]+\.[0-9]+% +[0-9]+\.[0-9]+% +$1 " > > +} > > + > > +perf_report_instruction_samples() { > > + echo "Looking at perf.data file for instruction samples:" > > + > > + # Below is an example of the instruction samples reporting: > > + # 68.12% touch libc-2.27.so [.] _dl_addr > > + # 5.80% touch libc-2.27.so [.] getenv > > + # 4.35% touch ld-2.27.so [.] _dl_fixup > > + perf report --itrace=i1000i --stdio -i ${perfdata} | \ > > + egrep " +[0-9]+\.[0-9]+% +$1" > > +} > > + > > +arm_cs_iterate_devices() { > > + for dev in $1/connections/out\:*; do > > + > > + # Skip testing if it's not a directory > > + ! [ -d $dev ] && continue; > > + > > + # Read out its symbol link file name > > + path=`readlink -f $dev` > > + > > + # Extract device name from path, e.g. > > + # path = '/sys/devices/platform/20010000.etf/tmc_etf0' > > + # `> device_name = 'tmc_etf0' > > + device_name=`echo $path | awk -F/ '{print $(NF)}'` > > + > > + echo $device_name | egrep -q "etr|etb|etf" > > Could we check for the existence of "enable_sink" instead, for detecting > if this is a sink device ? That way, we are covered for future cases of > a new sink type, and is more reliable. Good suggestion, will fix. > > + > > + # Only test if the output device is ETR/ETB/ETF > > + if [ $? -eq 0 ]; then > > + > > + > > pmu_dev="/sys/bus/event_source/devices/cs_etm/sinks/$device_name" > > + > > + # Exit if PMU device node doesn't exist > > + if ! [ -f $pmu_dev ]; then > > + echo "PMU device $pmu_dev doesn't exist" > > Misleading output. $pmu_dev is not a PMU device. Instead, it is one of > the supported sinks by the PMU. Will fix. > > + exit 1 > > + fi > > + > > + record_touch_file $device_name $2 && > > + perf_script_branch_samples touch && > > + perf_report_branch_samples touch && > > + perf_report_instruction_samples touch > > + > > + err=$? > > + > > + # Exit when find failure > > + [ $err != 0 ] && exit $err > > + > > + rm -f ${perfdata} > > + rm -f ${file} > > + fi > > + > > + arm_cs_iterate_devices $dev $2 > > + done > > +} > > + > > +arm_cs_etm_traverse_path_test() { > > + # Iterate for every ETM device > > + for dev in /sys/bus/coresight/devices/etm*; do > > + > > + # Find the ETM device belonging to which CPU > > + cpu=`cat $dev/cpu` > > + > > + echo $dev > > + echo $cpu > > + > > + # Use depth-first search (DFS) to iterate outputs > > + arm_cs_iterate_devices $dev $cpu > > + done > > +} > > + > > +arm_cs_etm_cpu_wide_test() { > > + echo "Recording trace with CPU wide mode" > > + perf record -o ${perfdata} -e cs_etm// -a -- ls > > + > > + perf_script_branch_samples perf && > > + perf_report_branch_samples perf && > > + perf_report_instruction_samples perf > > + > > + err=$? > > + > > + # Exit when find failure > > + [ $err != 0 ] && exit $err > > + > > + rm -f ${perfdata} > > + rm -f ${file} > > +} > > + > > +arm_cs_etm_snapshot_test() { > > + echo "Recording trace with snapshot mode" > > + perf record -o ${perfdata} -e cs_etm// -S --per-thread \ > > + -- dd if=/dev/zero of=/dev/null & > > As far as I understand, --per-thread option is not needed anymore > for normal tracing (irrespective of whether your application is > multi-threaded or not) I noted before you had some discussion with Mathieu for AUX buffer :) will remove --per-thread option. > > + PERFPID=$! > > + > > + # Wait for perf program > > + sleep 1 > > + > > + # Send signal to snapshot trace data > > + kill -USR2 $PERFPID > > + > > + # Stop perf program > > + kill $PERFPID > > + wait $PERFPID > > + > > + perf_script_branch_samples dd && > > + perf_report_branch_samples dd && > > + perf_report_instruction_samples dd > > + > > + err=$? > > + > > + # Exit when find failure > > + [ $err != 0 ] && exit $err > > + > > + rm -f ${perfdata} > > + rm -f ${file} > > +} > > + > > +arm_cs_etm_traverse_path_test > > +arm_cs_etm_cpu_wide_test > > +arm_cs_etm_snapshot_test > > +exit 0 > > > > > Rest looks OK to me. Thanks a lot for your reviewing. Leo
