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Message-ID: <050209c2-c784-e255-4e75-5c8674c5cfe0@foss.arm.com>
Date:   Thu, 21 Apr 2022 18:38:33 +0100
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Subject: Re: [PATCH 3/3] perf test: Add coresight tests to guage quality of
 data generated
Content-Language: en-US
To:     Leo Yan <leo.yan@linaro.org>
Cc:     linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
        suzuki.poulose@arm.com, mathieu.poirier@linaro.org,
        mike.leach@linaro.org, linux-perf-users@vger.kernel.org,
        acme@kernel.org
References: <20220309122859.31487-1-carsten.haitzler@foss.arm.com>
 <20220309122859.31487-3-carsten.haitzler@foss.arm.com>
 <20220410083041.GA184647@leoy-ThinkPad-X240s>
From:   Carsten Haitzler <carsten.haitzler@foss.arm.com>
Organization: Arm Ltd.
In-Reply-To: <20220410083041.GA184647@leoy-ThinkPad-X240s>
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Precedence: bulk


On 4/10/22 09:30, Leo Yan wrote:
> Hi Carsten,
> 
> On Wed, Mar 09, 2022 at 12:28:59PM +0000, carsten.haitzler@foss.arm.com wrote:
>> From: Carsten Haitzler <carsten.haitzler@arm.com>
>>
>> This adds a test harness and tests to run perf record and examine the
>> resuling output when coresight is enabled on arm64 and check the
>> resulting quality of the output as part of perf test. These tests use
>> various tools to produce output from perf record then measure some key
>> specific aspects of that data to see if the data exists at all and
>> contains key aspects such as measuring some data for every thread of
>> a test or produces sufficient data for large exeuction runs of a large
>> executable. etc.
>>
>> Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
>> ---
>>   MAINTAINERS                                   |   4 +
>>   tools/perf/.gitignore                         |   6 +-
>>   tools/perf/Documentation/arm-coresight.txt    | 140 ++++++++++++++++++
>>   tools/perf/Makefile.perf                      |  14 +-
>>   tools/perf/tests/shell/coresight/Makefile     |  30 ++++
>>   .../tests/shell/coresight/Makefile.miniconfig |  23 +++
>>   .../shell/coresight/asm_pure_loop/.gitignore  |   1 +
>>   .../shell/coresight/asm_pure_loop/Makefile    |  30 ++++
>>   .../coresight/asm_pure_loop/asm_pure_loop.S   |  28 ++++
>>   .../shell/coresight/memcpy_thread/.gitignore  |   1 +
>>   .../shell/coresight/memcpy_thread/Makefile    |  29 ++++
>>   .../coresight/memcpy_thread/memcpy_thread.c   |  79 ++++++++++
>>   .../shell/coresight/thread_loop/.gitignore    |   1 +
>>   .../shell/coresight/thread_loop/Makefile      |  29 ++++
>>   .../shell/coresight/thread_loop/thread_loop.c |  86 +++++++++++
>>   .../coresight/unroll_loop_thread/.gitignore   |   1 +
>>   .../coresight/unroll_loop_thread/Makefile     |  29 ++++
>>   .../unroll_loop_thread/unroll_loop_thread.c   |  74 +++++++++
>>   .../tests/shell/coresight_asm_pure_loop.sh    |  18 +++
>>   .../shell/coresight_memcpy_thread_16k_10.sh   |  18 +++
>>   .../coresight_thread_loop_check_tid_10.sh     |  19 +++
>>   .../coresight_thread_loop_check_tid_2.sh      |  19 +++
>>   .../shell/coresight_unroll_loop_thread_10.sh  |  18 +++
>>   tools/perf/tests/shell/lib/coresight.sh       | 130 ++++++++++++++++
> 
> Very big change...  Why squash all patches form previous verion to this
> single one big patch?  Usually the format with small patches is much
> better for reviewing.

I was asked to re-jig the tree and in doing so I also ended up cutting 
down the size a lot so this just makes more sense together as a "here 
are the tests" as adding infra without any tests makes no sense and the 
tests themelves are self-contained in their own directories and source 
files and "drivign scripts" thus it's essentially patch 1 appended to 
patch 2 to patch 3 etc. and still broken up in the patch file by file.

> And I cannot apply cleanly on perf core branch:
> https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git branch: perf/core.

I generated this based on tip. I can re-do it based on the above.

>>   24 files changed, 823 insertions(+), 4 deletions(-)
>>   create mode 100644 tools/perf/Documentation/arm-coresight.txt
>>   create mode 100644 tools/perf/tests/shell/coresight/Makefile
>>   create mode 100644 tools/perf/tests/shell/coresight/Makefile.miniconfig
>>   create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
>>   create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
>>   create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S
>>   create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/.gitignore
>>   create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/Makefile
>>   create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c
>>   create mode 100644 tools/perf/tests/shell/coresight/thread_loop/.gitignore
>>   create mode 100644 tools/perf/tests/shell/coresight/thread_loop/Makefile
>>   create mode 100644 tools/perf/tests/shell/coresight/thread_loop/thread_loop.c
>>   create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/.gitignore
>>   create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/Makefile
>>   create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
>>   create mode 100755 tools/perf/tests/shell/coresight_asm_pure_loop.sh
>>   create mode 100755 tools/perf/tests/shell/coresight_memcpy_thread_16k_10.sh
>>   create mode 100755 tools/perf/tests/shell/coresight_thread_loop_check_tid_10.sh
>>   create mode 100755 tools/perf/tests/shell/coresight_thread_loop_check_tid_2.sh
>>   create mode 100755 tools/perf/tests/shell/coresight_unroll_loop_thread_10.sh
>>   create mode 100644 tools/perf/tests/shell/lib/coresight.sh
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 673c7124ca82..18cc20609f2e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -1918,10 +1918,14 @@ F:	drivers/hwtracing/coresight/*
>>   F:	include/dt-bindings/arm/coresight-cti-dt.h
>>   F:	include/linux/coresight*
>>   F:	samples/coresight/*
>> +F:	tools/perf/Documentation/arm-coresight.txt
>>   F:	tools/perf/arch/arm/util/auxtrace.c
>>   F:	tools/perf/arch/arm/util/cs-etm.c
>>   F:	tools/perf/arch/arm/util/cs-etm.h
>>   F:	tools/perf/arch/arm/util/pmu.c
>> +F:	tools/perf/tests/shell/coresight_*
>> +F:	tools/perf/tests/shell/tools/Makefile
>> +F:	tools/perf/tests/shell/tools/coresight/*
>>   F:	tools/perf/util/cs-etm-decoder/*
>>   F:	tools/perf/util/cs-etm.*
>>   
>> diff --git a/tools/perf/.gitignore b/tools/perf/.gitignore
>> index 20b8ab984d5f..138c679ecacd 100644
>> --- a/tools/perf/.gitignore
>> +++ b/tools/perf/.gitignore
>> @@ -15,8 +15,9 @@ perf*.1
>>   perf*.xml
>>   perf*.html
>>   common-cmds.h
>> -perf.data
>> -perf.data.old
>> +perf*.data
>> +perf*.data.old
>> +stats-*.csv
>>   output.svg
>>   perf-archive
>>   perf-with-kcore
>> @@ -30,6 +31,7 @@ config.mak.autogen
>>   *-flex.*
>>   *.pyc
>>   *.pyo
>> +*.stdout
>>   .config-detected
>>   util/intel-pt-decoder/inat-tables.c
>>   arch/*/include/generated/
>> diff --git a/tools/perf/Documentation/arm-coresight.txt b/tools/perf/Documentation/arm-coresight.txt
>> new file mode 100644
>> index 000000000000..3a9e6c573c58
>> --- /dev/null
>> +++ b/tools/perf/Documentation/arm-coresight.txt
>> @@ -0,0 +1,140 @@
>> +Arm Coresight Support
>> +=====================
>> +
>> +Coresight is a feature of some Arm based processors that allows for
>> +debugging. One of the things it can do is trace every instruction
>> +executed and remotely expose that information in a hardware compressed
>> +stream.
> 
> Maybe here need to sync a bit for the terminology in
> Documentation/trace/coresight/coresight.rst.
> 
> Something like:
> 
> "Coresight is a feature of some Arm based processors that allows for
> debugging. One of the things it can do is trace instruction path and
> expose that information in a hardware compressed stream for either
> debugger or HW assisted tracing locally.
> 
> See Documentation/trace/coresight/coresight.rst for details."

Sure. Can do that.

>> Perf is able to locally access that stream and store it to the
>> +output perf data files. This stream can then be later decoded to give the
>> +instructions that were traced for debugging or profiling purposes. You
>> +can log such data with a perf record command like:
>> +
>> +    perf record -e cs_etm//u testbinary
>> +
>> +This would run some test binary (testbinary) until it exits and record
>> +a perf.data trace file. That file would have AUX sections if coresight
>> +is working correctly. You can dump the content of this file as
>> +readable text with a command like:
>> +
>> +    perf report --stdio --dump -i perf.data
>> +
>> +You should find some sections of this file have AUX data blocks like:
>> +
>> +    0x1e78 [0x30]: PERF_RECORD_AUXTRACE size: 0x11dd0  offset: 0  ref: 0x1b614fc1061b0ad1  idx: 0  tid: 531230  cpu: -1
>> +
>> +    . ... CoreSight ETM Trace data: size 73168 bytes
>> +            Idx:0; ID:10;   I_ASYNC : Alignment Synchronisation.
>> +              Idx:12; ID:10;  I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 }
>> +              Idx:17; ID:10;  I_ADDR_L_64IS0 : Address, Long, 64 bit, IS0.; Addr=0x0000000000000000;
>> +              Idx:26; ID:10;  I_TRACE_ON : Trace On.
>> +              Idx:27; ID:10;  I_ADDR_CTXT_L_64IS0 : Address & Context, Long, 64 bit, IS0.; Addr=0x0000FFFFB6069140; Ctxt: AArch64,EL0, NS;
>> +              Idx:38; ID:10;  I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE
>> +              Idx:39; ID:10;  I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE
>> +              Idx:40; ID:10;  I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE
>> +              Idx:41; ID:10;  I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEN
>> +              ...
>> +
>> +If you see these above, then your system is tracing coresight data
>> +correctly.
>> +
>> +To compile perf with coresight support in the perf directory do
>> +
>> +    make CORESIGHT=1
> 
> It is inaccurate that if we don't mention openCSD lib.

Do you mean I need to mention that you need the opencsd library 
installed too?

>> +
>> +This will compile the perf tool with coresight support as well as
>> +build some small test binaries for perf test. This requires you also
>> +be compiling for 64bit Arm (ARM64/aarch64). The tools run as part of
>> +perf coresight tracing are in tests/shell/tools/coresight.
> 
> For build perf tool, I think above paragraphs are duplicate with the
> document Documentation/trace/coresight/coresight.rst.  Can we simply
> say:
> 
> "The details for building perf tool with support Arm Coresight can be
> found in the "HOWTO.md" file of the openCSD gitHub repository:
> https://github.com/Linaro/opencsd.

I can. I put this here as I didn't go clone OpencCSD first but used my 
distro OpenCSD packages and thus of course didn't have the documentation 
in front of me. I spent some time wondering why it wasn't building with 
coresight support even though it detected OpenCSD when I compiled... I 
didn't expect to have to go to some separate project git repository and 
read docs there on how to build the perf tool here in the kernel. I 
wrote this because it was an actual problem I hit and it's a lot less 
frustrating to "end users" to give them the information they need in the 
relevant place they need it instead of sending them around to other 
project trees. Building perf with coresight support is handled by the 
perf tree int he kernel, not OpenCSD, thus IMHO that is where the 
documentation belongs - alongside the thing that determines how to build 
something.

> And "HOWTO.md" file gives the information and examples for how to use
> perf tool to record and report Coresight trace data.  It's the
> prerequisite for this perf Coresight test."
> 
>> +You will also want coresight support enabled in your kernel config.
>> +Ensure it is enabled with:
>> +
>> +    CONFIG_CORESIGHT=y
>> +
>> +There are various other coresight options you probably also want
>> +enabled like:
>> +
>> +    CONFIG_CORESIGHT_LINKS_AND_SINKS=y
>> +    CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
>> +    CONFIG_CORESIGHT_CATU=y
>> +    CONFIG_CORESIGHT_SINK_TPIU=y
>> +    CONFIG_CORESIGHT_SINK_ETBV10=y
>> +    CONFIG_CORESIGHT_SOURCE_ETM4X=y
>> +    CONFIG_CORESIGHT_STM=y
>> +    CONFIG_CORESIGHT_CPU_DEBUG=y
>> +    CONFIG_CORESIGHT_CTI=y
>> +    CONFIG_CORESIGHT_CTI_INTEGRATION_REGS=y
>> +
>> +Please refer to the kernel configuration help for more information.
> 
> I prefer to remove these kernel configuration since they are not
> inconsistent on different platforms (e.g. ETBV10, ETM4X, etc), and
> some configurations might not necessary (e.g. CPU_DEBUG).

Certainly there should be some documentation on which kernel configs you 
might want to turn on then? Imagine someone new comes along and doesn't 
have any idea what to possible enable at all and manages to build perf 
with coresight support (as above) then finds it doesn't work because 
they didn't enable enough config in the kernel? Sure - could probably 
trim these down a bit but the point here is to alert the user to there 
being a range of coresight config options that you need to turn on that 
you likely will find are not turned on. They certainly are not turned on 
on distro kernels and a lot of the time when you have a platform that 
already boots/works you start with your distro kernel config file 
because you want everything enabled so it actually boots. I've learned 
the hard way to do this as you manage to forget to turn on some MMC 
driver or some other feature and your boot hangs or doesn't find rootfs etc.

What would you recommend then as a "turn these on and coresight will 
almost certainly work for you on your given hardware " then?

>> +Perf test - Verify kernel and userspace perf coresight work
>> +===========================================================
>> +
>> +When you run perf test, it will do a lot of self tests. Some of those
>> +tests will cover Coresight (only if enabled and on ARM64). You
>> +generally would run perf test from the tools/perf directory in the
>> +kernel tree. Some tests will check some internal perf support like:
>> +
>> +    Check Arm CoreSight trace data recording and synthesized samples
>> +
>> +Some others will actually use perf record and some test binaries that
>> +are in tests/shell/tools/coresight and will collect traces to ensure a
>> +minimum level of functionality is met. The scripts that launch these
>> +tests are in tests/shell. These will all look like:
>> +
>> +    Coresight / Memcpy 1M 25 Threads
>> +    Coresight / Unroll Loop Thread 2
>> +    ...
> 
> Please update based on the latest test case names, at my side, I can
> see the testing case like:
> 
>         Coresight / ASM Pure Loop
>         Coresight / Memcpy 16k 10 Threads
>         Coresight / Thread Loop 10 Threads - Check TID
>         Coresight / Thread Loop 2 Threads - Check TID
>         Coresight / Unroll Loop Thread 10

Oh sorry - yeah. I wrote the docs based on the earlier tests. Will fix.

>> +
>> +These perf record tests will not run if the tool binaries do not exist
>> +in tests/shell/tools/coresight/*/ and will be skipped. If you do not
>> +have coresight support in hardware then either do not build perf with
>> +coresight support or remove these binaries in order to not have these
>> +tests fail and have them skip instead.
>> +
>> +These tests will log historical results in the current working
>> +directory (e.g. tools/perf) and will be named stats-*.csv like:
>> +
>> +    stats-asm_pure_loop-out.csv
>> +    stats-bubble_sort-random.csv
>> +    ...
>> +
>> +These statistic files log some aspects of the AUX data sections in
>> +the perf data output counting some numbers of certain encodings (a
>> +good way to know that it's working in a very simple way). One problem
>> +with coresight is that given a large enough amount of data needing to
>> +be logged, some of it can be lost due to the processor not waking up
>> +in time to read out all the data from buffers etc.. You will notice
>> +that the amount of data collected can vary a lot per run of perf test.
>> +If you wish to see how this changes over time, simply run perf test
>> +multiple times and all these csv files will have more and more data
>> +appended to it that you can later examine, graph and otherwise use to
>> +figure out if things have become worse or better.
> 
> I am confused by this narrative.  Does it try to remind that the final
> testing result (pass or fail) is not stable?  Or should we run for
> multiple times so have more chance to capture issues?

That is correct. I thought I was clear that it's lossy. That is actually 
the case. I have tests here that actually fail because there is no data 
collected from some threads at all (missing CID blocks for some of the 
threads that run in the test). The point is to have tests that may be 
failing now but in future will improve. I lowered the minimum bar to 
pass for most tests to have "at least just a little data" but most tests 
show highly variable amount of captured data. the csv files are there to 
over-time give you a good idea of the stability of the captured data.

>> +Be aware that amny of these tests take quite a while to run, specifically
> 
> s/amny/many

Indeed. will fix.

>> +in processing the perf data file and dumping contents to then examine what
>> +is inside.
>> +
>> +You can change where these csv logs are stored by setting the
>> +PERF_TEST_CORESIGHT_STATDIR environment variable before running perf
>> +test like:
>> +
>> +    export PERF_TEST_CORESIGHT_STATDIR=/var/tmp
>> +    perf test
>> +
>> +They will also store resulting perf output data in the current
>> +directory for later inspection like:
>> +
>> +    perf-memcpy-1m.data
>> +    perf-thread_loop-2th.data
>> +    ...
>> +
>> +You can alter where the perf data files are stored by setting the
>> +PERF_TEST_CORESIGHT_DATADIR environment variable such as:
>> +
>> +    PERF_TEST_CORESIGHT_DATADIR=/var/tmp
>> +    perf test
>> +
>> +You may wish to set these above environment variables if you which to
>> +keep the output of tests outside of the current working directory for
>> +longer term storage and examination.
>> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
>> index ac861e42c8f7..b97db83992e0 100644
>> --- a/tools/perf/Makefile.perf
>> +++ b/tools/perf/Makefile.perf
>> @@ -630,7 +630,15 @@ sync_file_range_tbls := $(srctree)/tools/perf/trace/beauty/sync_file_range.sh
>>   $(sync_file_range_arrays): $(linux_uapi_dir)/fs.h $(sync_file_range_tbls)
>>   	$(Q)$(SHELL) '$(sync_file_range_tbls)' $(linux_uapi_dir) > $@
>>   
>> -all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
>> +TESTS_CORESIGHT_DIR := $(srctree)/tools/perf/tests/shell/coresight
>> +
>> +tests-coresight-targets: FORCE
>> +	$(Q)$(MAKE) -C $(TESTS_CORESIGHT_DIR)
>> +
>> +tests-coresight-targets-clean:
>> +	$(Q)$(MAKE) -C $(TESTS_CORESIGHT_DIR) clean
>> +
>> +all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS) tests-coresight-targets
>>   
>>   # Create python binding output directory if not already present
>>   _dummy := $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
>> @@ -1020,6 +1028,7 @@ install-tests: all install-gtk
>>   		$(INSTALL) tests/shell/*.sh '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell'; \
>>   		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/lib'; \
>>   		$(INSTALL) tests/shell/lib/*.sh '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/lib'
>> +	$(Q)$(MAKE) -C tests/shell/coresight install-tests
>>   
>>   install-bin: install-tools install-tests install-traceevent-plugins
>>   
>> @@ -1088,7 +1097,7 @@ endif # BUILD_BPF_SKEL
>>   bpf-skel-clean:
>>   	$(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TMP_OUT) $(SKELETONS)
>>   
>> -clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean fixdep-clean python-clean bpf-skel-clean
>> +clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean fixdep-clean python-clean bpf-skel-clean tests-coresight-targets-clean
>>   	$(call QUIET_CLEAN, core-objs)  $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf-iostat $(LANG_BINDINGS)
>>   	$(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
>>   	$(Q)$(RM) $(OUTPUT).config-detected
>> @@ -1155,5 +1164,6 @@ FORCE:
>>   .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell
>>   .PHONY: $(GIT-HEAD-PHONY) TAGS tags cscope FORCE prepare
>>   .PHONY: libtraceevent_plugins archheaders
>> +.PHONY: $(TESTS_CORESIGHT_TARGETS)
> 
> I don't find other places using TESTS_CORESIGHT_TARGETS.  Is this
> redundant?

I'll check - it may have been left over from my previous patch set.

>>   endif # force_fixdep
>> diff --git a/tools/perf/tests/shell/coresight/Makefile b/tools/perf/tests/shell/coresight/Makefile
>> new file mode 100644
>> index 000000000000..dda99aeac158
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/Makefile
>> @@ -0,0 +1,30 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +include ../../../../../tools/scripts/Makefile.include
>> +include ../../../../../tools/scripts/Makefile.arch
>> +include ../../../../../tools/scripts/utilities.mak
>> +
>> +SUBDIRS = \
>> +	asm_pure_loop \
>> +	thread_loop \
>> +	memcpy_thread \
>> +	unroll_loop_thread
>> +
>> +all: $(SUBDIRS)
>> +$(SUBDIRS):
>> +	$(Q)$(MAKE) -C $@
>> +
>> +INSTALLDIRS = $(SUBDIRS:%=install-%)
>> +
>> +install-tests: $(INSTALLDIRS)
>> +$(INSTALLDIRS):
>> +	$(Q)$(MAKE) -C $(@:install-%=%) install-tests
>> +
>> +CLEANDIRS = $(SUBDIRS:%=clean-%)
>> +
>> +clean: $(CLEANDIRS)
>> +$(CLEANDIRS):
>> +	$(Q)$(MAKE) -C $(@:clean-%=%) clean >/dev/null
>> +
>> +.PHONY: all clean $(SUBDIRS) $(CLEANDIRS) $(INSTALLDIRS)
>> +
>> diff --git a/tools/perf/tests/shell/coresight/Makefile.miniconfig b/tools/perf/tests/shell/coresight/Makefile.miniconfig
>> new file mode 100644
>> index 000000000000..893c12685fed
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/Makefile.miniconfig
>> @@ -0,0 +1,23 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +ifndef DESTDIR
>> +prefix ?= $(HOME)
>> +endif
>> +
>> +DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
>> +perfexecdir = libexec/perf-core
>> +perfexec_instdir = $(perfexecdir)
>> +
>> +ifneq ($(filter /%,$(firstword $(perfexecdir))),)
>> +perfexec_instdir = $(perfexecdir)
>> +else
>> +perfexec_instdir = $(prefix)/$(perfexecdir)
>> +endif
>> +
>> +perfexec_instdir_SQ = $(subst ','\'',$(perfexec_instdir))
>> +INSTALL = install
>> +
>> +include ../../../../../scripts/Makefile.include
>> +include ../../../../../scripts/Makefile.arch
>> +include ../../../../../scripts/utilities.mak
>> diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore b/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
>> new file mode 100644
>> index 000000000000..468673ac32e8
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore
>> @@ -0,0 +1 @@
>> +asm_pure_loop
> 
> Do we really need there '.gitignore' files under the folder
> 'tools/perf/tests/shell/coresight/'.

Where would you rather have them to ignore the generated binary tools?

>> diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile b/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
>> new file mode 100644
>> index 000000000000..10c5a60cb71c
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/asm_pure_loop/Makefile
>> @@ -0,0 +1,30 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +include ../Makefile.miniconfig
>> +
>> +BIN=asm_pure_loop
>> +LIB=
> 
> Remove the unused variable 'LIB='.

I have this because I wanted to have a simple template to be able to 
re-use for more tests over time. It's so much easier to maintain and 
extend if every makefile and tool follow a similar pattern and you can 
almost copy & paste between them as they don't have "exceptions". You 
really want me to remove this?

>> +
>> +all: $(BIN)
>> +
>> +$(BIN): $(BIN).S
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(Q)$(CC) $(BIN).S -nostdlib -static -o $(BIN) $(LIB)
>> +endif
>> +endif
>> +
>> +install-tests: all
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(call QUIET_INSTALL, tests) \
>> +		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)'; \
>> +		$(INSTALL) $(BIN) '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)/$(BIN)'
>> +endif
>> +endif
>> +
>> +clean:
>> +	$(Q)$(RM) -f $(BIN)
>> +
>> +.PHONY: all clean install-tests
> 
> There have four sub folders under tools/perf/tests/shell/coresight:
> 
>    asm_pure_loop
>    memcpy_thread
>    thread_loop
>    unroll_loop_thread
> 
> And every folder has its own Makefile and every Makefile is quite
> close to each other.  I am just wandering if it's possible to
> remove the 4 Makefiles in these four sub folders, and simply use
> tools/perf/tests/shell/coresight/Makefile as the central place to
> build these assistant programs.

I did this so it's easier to etxent over time. having a single parent 
makefile that over time accumulates little ugly "if's" and exceptions 
makes longer-term maintenance and extending harder. I did it this way to 
make this easy - make a copy of a dir - add that dir to a parent 
makefile then modify the makefile as needed (but only as needed).

>> diff --git a/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S b/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S
>> new file mode 100644
>> index 000000000000..75cf084a927d
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S
>> @@ -0,0 +1,28 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Tamas Zsoldos <tamas.zsoldos@arm.com>, 2021 */
>> +
>> +.globl _start
>> +_start:
>> +	mov	x0, 0x0000ffff
>> +	mov	x1, xzr
>> +loop:
>> +	nop
>> +	nop
>> +	cbnz	x1, noskip
>> +	nop
>> +	nop
>> +	adrp	x2, skip
>> +	add 	x2, x2, :lo12:skip
>> +	br	x2
>> +	nop
>> +	nop
>> +noskip:
>> +	nop
>> +	nop
>> +skip:
>> +	sub	x0, x0, 1
>> +	cbnz	x0, loop
>> +
>> +	mov	x0, #0
>> +	mov	x8, #93 // __NR_exit syscall
>> +	svc	#0
> 
> I tested the case "ASM Pure Loop" on my Juno board, and it complaints:
> 
> root@debian:/mnt/export/arm-linux-kernel/tools/perf# ./perf test -v 76
>   76: Coresight / ASM Pure Loop                                       :
> --- start ---
> test child forked, pid 9063
> failed to mmap with 12 (Cannot allocate memory)
> test child finished with -1
> ---- end ----
> Coresight / ASM Pure Loop: FAILED!
> 
> Since I only setup the 1GB memory for the Linux kernel, it fails to
> allocate AUX ring buffer with the size 256MB.  So I manully change
> the buffer size to 8MB in tools/perf/tests/shell/lib/coresight.sh:
> 
>    PERFRECMEM="-m ,8M"
> 
> So finally I can see the test case is passed:

This is artificial isn't it? limiting to 1GB. You certainly have far 
more memory than that available. My testse were on a system with 4GB and 
I had no issues.

> root@debian:/mnt/export/arm-linux-kernel/tools/perf# ./perf test -v 76
>   76: Coresight / ASM Pure Loop                                       :
> --- start ---
> test child forked, pid 9481
> -m ,8M -e cs_etm//u
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.681 MB ./perf-asm_pure_loop-out.data ]
> test child finished with 0
> ---- end ----
> Coresight / ASM Pure Loop: Ok
> 
> Do you think we really need to use 256MiB as the AUX buffer size?
> IIRC, it means we allocate 256MiB per CPU for this case, on the other
> hand, you could see the final perf data file size is small (0.681
> MiB).
> 
> Seems to me, it's not necessary to allocate so big buffer for
> the test, and I tried to run below 4 cases with 8MiB, all of them can
> pass the testing :)

I didn't think anyone with a system with coresight support that would be 
running perf record locally would only have 1GB of ram... I knew junos 
had 8GB and my dragonboard has 4GB ... so I know I was on the smaller 
side. I thought a larger buffer == safer results (less chance of needing 
to write out the buffer during capture). Admittdly I used 256Mb when my 
tests ran for much longer and collected more data. I can try drop to 8 
or 16gb and see.

>> diff --git a/tools/perf/tests/shell/coresight/memcpy_thread/.gitignore b/tools/perf/tests/shell/coresight/memcpy_thread/.gitignore
>> new file mode 100644
>> index 000000000000..f8217e56091e
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/memcpy_thread/.gitignore
>> @@ -0,0 +1 @@
>> +memcpy_thread
>> diff --git a/tools/perf/tests/shell/coresight/memcpy_thread/Makefile b/tools/perf/tests/shell/coresight/memcpy_thread/Makefile
>> new file mode 100644
>> index 000000000000..e2604cfae74b
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/memcpy_thread/Makefile
>> @@ -0,0 +1,29 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +include ../Makefile.miniconfig
>> +
>> +BIN=memcpy_thread
>> +LIB=-pthread
>> +
>> +all: $(BIN)
>> +
>> +$(BIN): $(BIN).c
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(Q)$(CC) $(BIN).c -o $(BIN) $(LIB)
>> +endif
>> +endif
>> +
>> +install-tests: all
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(call QUIET_INSTALL, tests) \
>> +		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)'; \
>> +		$(INSTALL) $(BIN) '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)/$(BIN)'
>> +endif
>> +endif
>> +
>> +clean:
>> +	$(Q)$(RM) -f $(BIN)
>> +
>> +.PHONY: all clean install-tests
>> diff --git a/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c b/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c
>> new file mode 100644
>> index 000000000000..a7e169d1bf64
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c
>> @@ -0,0 +1,79 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include <pthread.h>
>> +
>> +struct args {
>> +	unsigned long loops;
>> +	unsigned long size;
>> +	pthread_t th;
>> +	void *ret;
>> +};
>> +
>> +static void *thrfn(void *arg)
>> +{
>> +	struct args *a = arg;
>> +	unsigned long i, len = a->loops;
>> +	unsigned char *src, *dst;
>> +
>> +	src = malloc(a->size * 1024);
>> +	dst = malloc(a->size * 1024);
>> +	if ((!src) || (!dst)) {
>> +		printf("ERR: Can't allocate memory\n");
>> +		exit(1);
>> +	}
>> +	for (i = 0; i < len; i++)
>> +		memcpy(dst, src, a->size * 1024);
>> +}
>> +
>> +static pthread_t new_thr(void *(*fn) (void *arg), void *arg)
>> +{
>> +	pthread_t t;
>> +	pthread_attr_t attr;
>> +
>> +	pthread_attr_init(&attr);
>> +	pthread_create(&t, &attr, fn, arg);
>> +	return t;
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> +	unsigned long i, len, size, thr;
>> +	pthread_t threads[256];
>> +	struct args args[256];
>> +	long long v;
>> +
>> +	if (argc < 4) {
>> +		printf("ERR: %s [copysize Kb] [numthreads] [numloops (hundreds)]\n", argv[0]);
>> +		exit(1);
>> +	}
>> +
>> +	v = atoll(argv[1]);
>> +	if ((v < 1) || (v > (1024 * 1024))) {
>> +		printf("ERR: max memory 1GB (1048576 KB)\n");
>> +		exit(1);
>> +	}
>> +	size = v;
>> +	thr = atol(argv[2]);
>> +	if ((thr < 1) || (thr > 256)) {
>> +		printf("ERR: threads 1-256\n");
>> +		exit(1);
>> +	}
>> +	v = atoll(argv[3]);
>> +	if ((v < 1) || (v > 40000000000ll)) {
>> +		printf("ERR: loops 1-40000000000 (hundreds)\n");
>> +		exit(1);
>> +	}
>> +	len = v * 100;
>> +	for (i = 0; i < thr; i++) {
>> +		args[i].loops = len;
>> +		args[i].size = size;
>> +		args[i].th = new_thr(thrfn, &(args[i]));
>> +	}
>> +	for (i = 0; i < thr; i++)
>> +		pthread_join(args[i].th, &(args[i].ret));
>> +	return 0;
>> +}
>> diff --git a/tools/perf/tests/shell/coresight/thread_loop/.gitignore b/tools/perf/tests/shell/coresight/thread_loop/.gitignore
>> new file mode 100644
>> index 000000000000..6d4c33eaa9e8
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/thread_loop/.gitignore
>> @@ -0,0 +1 @@
>> +thread_loop
>> diff --git a/tools/perf/tests/shell/coresight/thread_loop/Makefile b/tools/perf/tests/shell/coresight/thread_loop/Makefile
>> new file mode 100644
>> index 000000000000..424df4e8b0e6
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/thread_loop/Makefile
>> @@ -0,0 +1,29 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +include ../Makefile.miniconfig
>> +
>> +BIN=thread_loop
>> +LIB=-pthread
>> +
>> +all: $(BIN)
>> +
>> +$(BIN): $(BIN).c
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(Q)$(CC) $(BIN).c -o $(BIN) $(LIB)
>> +endif
>> +endif
>> +
>> +install-tests: all
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(call QUIET_INSTALL, tests) \
>> +		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)'; \
>> +		$(INSTALL) $(BIN) '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)/$(BIN)'
>> +endif
>> +endif
>> +
>> +clean:
>> +	$(Q)$(RM) -f $(BIN)
>> +
>> +.PHONY: all clean install-tests
>> diff --git a/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c b/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c
>> new file mode 100644
>> index 000000000000..c0158fac7d0b
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/thread_loop/thread_loop.c
>> @@ -0,0 +1,86 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +// define this for gettid()
>> +#define _GNU_SOURCE
>> +
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include <pthread.h>
>> +#include <sys/syscall.h>
>> +#ifndef SYS_gettid
>> +// gettid is 178 on arm64
>> +# define SYS_gettid 178
>> +#endif
>> +#define gettid() syscall(SYS_gettid)
>> +
>> +struct args {
>> +	unsigned int loops;
>> +	pthread_t th;
>> +	void *ret;
>> +};
>> +
>> +static void *thrfn(void *arg)
>> +{
>> +	struct args *a = arg;
>> +	int i = 0, len = a->loops;
>> +
>> +	if (getenv("SHOW_TID")) {
>> +		unsigned long long tid = gettid();
>> +
>> +		printf("%llu\n", tid);
>> +	}
>> +	asm volatile(
>> +		"loop:\n"
>> +		"add %[i], %[i], #1\n"
>> +		"cmp %[i], %[len]\n"
>> +		"blt loop\n"
>> +		: /* out */
>> +		: /* in */ [i] "r" (i), [len] "r" (len)
>> +		: /* clobber */
>> +	);
>> +	return (void *)(long)i;
>> +}
>> +
>> +static pthread_t new_thr(void *(*fn) (void *arg), void *arg)
>> +{
>> +	pthread_t t;
>> +	pthread_attr_t attr;
>> +
>> +	pthread_attr_init(&attr);
>> +	pthread_create(&t, &attr, fn, arg);
>> +	return t;
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> +	unsigned int i, len, thr;
>> +	pthread_t threads[256];
>> +	struct args args[256];
>> +
>> +	if (argc < 3) {
>> +		printf("ERR: %s [numthreads] [numloops (millions)]\n", argv[0]);
>> +		exit(1);
>> +	}
>> +
>> +	thr = atoi(argv[1]);
>> +	if ((thr < 1) || (thr > 256)) {
>> +		printf("ERR: threads 1-256\n");
>> +		exit(1);
>> +	}
>> +	len = atoi(argv[2]);
>> +	if ((len < 1) || (len > 4000)) {
>> +		printf("ERR: max loops 4000 (millions)\n");
>> +		exit(1);
>> +	}
>> +	len *= 1000000;
>> +	for (i = 0; i < thr; i++) {
>> +		args[i].loops = len;
>> +		args[i].th = new_thr(thrfn, &(args[i]));
>> +	}
>> +	for (i = 0; i < thr; i++)
>> +		pthread_join(args[i].th, &(args[i].ret));
>> +	return 0;
>> +}
>> diff --git a/tools/perf/tests/shell/coresight/unroll_loop_thread/.gitignore b/tools/perf/tests/shell/coresight/unroll_loop_thread/.gitignore
>> new file mode 100644
>> index 000000000000..2cb4e996dbf3
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/unroll_loop_thread/.gitignore
>> @@ -0,0 +1 @@
>> +unroll_loop_thread
>> diff --git a/tools/perf/tests/shell/coresight/unroll_loop_thread/Makefile b/tools/perf/tests/shell/coresight/unroll_loop_thread/Makefile
>> new file mode 100644
>> index 000000000000..45ab2be8be92
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/unroll_loop_thread/Makefile
>> @@ -0,0 +1,29 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +include ../Makefile.miniconfig
>> +
>> +BIN=unroll_loop_thread
>> +LIB=-pthread
>> +
>> +all: $(BIN)
>> +
>> +$(BIN): $(BIN).c
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(Q)$(CC) $(BIN).c -o $(BIN) $(LIB)
>> +endif
>> +endif
>> +
>> +install-tests: all
>> +ifdef CORESIGHT
>> +ifeq ($(ARCH),arm64)
>> +	$(call QUIET_INSTALL, tests) \
>> +		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)'; \
>> +		$(INSTALL) $(BIN) '$(DESTDIR_SQ)$(perfexec_instdir_SQ)/tests/shell/tools/$(BIN)/$(BIN)'
>> +endif
>> +endif
>> +
>> +clean:
>> +	$(Q)$(RM) -f $(BIN)
>> +
>> +.PHONY: all clean install-tests
>> diff --git a/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
>> new file mode 100644
>> index 000000000000..cb9d22c7dfb9
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
>> @@ -0,0 +1,74 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include <pthread.h>
>> +
>> +struct args {
>> +	pthread_t th;
>> +	unsigned int in, out;
>> +	void *ret;
>> +};
>> +
>> +static void *thrfn(void *arg)
>> +{
>> +	struct args *a = arg;
>> +	unsigned int i, in = a->in;
>> +
>> +	for (i = 0; i < 10000; i++) {
>> +		asm volatile (
>> +// force an unroll of thia add instruction so we can test long runs of code
>> +#define SNIP1 "add %[in], %[in], #1\n"
>> +// 10
>> +#define SNIP2 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1
>> +// 100
>> +#define SNIP3 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2
>> +// 1000
>> +#define SNIP4 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3
>> +// 10000
>> +#define SNIP5 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4
>> +// 100000
>> +			SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5
>> +			: /* out */
>> +			: /* in */ [in] "r" (in)
>> +			: /* clobber */
>> +		);
>> +	}
>> +}
>> +
>> +static pthread_t new_thr(void *(*fn) (void *arg), void *arg)
>> +{
>> +	pthread_t t;
>> +	pthread_attr_t attr;
>> +
>> +	pthread_attr_init(&attr);
>> +	pthread_create(&t, &attr, fn, arg);
>> +	return t;
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> +	unsigned int i, thr;
>> +	pthread_t threads[256];
>> +	struct args args[256];
>> +
>> +	if (argc < 2) {
>> +		printf("ERR: %s [numthreads]\n", argv[0]);
>> +		exit(1);
>> +	}
>> +
>> +	thr = atoi(argv[1]);
>> +	if ((thr > 256) || (thr < 1)) {
>> +		printf("ERR: threads 1-256\n");
>> +		exit(1);
>> +	}
>> +	for (i = 0; i < thr; i++) {
>> +		args[i].in = rand();
>> +		args[i].th = new_thr(thrfn, &(args[i]));
>> +	}
>> +	for (i = 0; i < thr; i++)
>> +		pthread_join(args[i].th, &(args[i].ret));
>> +	return 0;
>> +}
>> diff --git a/tools/perf/tests/shell/coresight_asm_pure_loop.sh b/tools/perf/tests/shell/coresight_asm_pure_loop.sh
>> new file mode 100755
>> index 000000000000..3f0dbefcad50
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight_asm_pure_loop.sh
>> @@ -0,0 +1,18 @@
>> +#!/bin/sh -e
>> +# Coresight / ASM Pure Loop
>> +
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +TEST="asm_pure_loop"
>> +. $(dirname $0)/lib/coresight.sh
>> +ARGS=""
>> +DATV="out"
>> +DATA="$DATD/perf-$TEST-$DATV.data"
>> +
>> +perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS
>> +
>> +perf_dump_aux_verify "$DATA" 10 10 10
>> +
>> +err=$?
>> +exit $err
> 
> Can we organize the shell scripts by moving them into the folder
> tools/perf/tests/shell/coresight?

We can - but it comes with a fair few more changes.

>    coresight_asm_pure_loop.sh
>    coresight_memcpy_thread_16k_10.sh
>    coresight_thread_loop_check_tid_10.sh
>    coresight_thread_loop_check_tid_2.sh
>    coresight_unroll_loop_thread_10.sh
> 
> And we even can consider to move script test_arm_coresight.sh into
> the folder tools/perf/tests/shell/coresight and change its
> name as 'coresight_smoke_test.sh'.

Indeed these other tests I left alone for now and had not thought about 
how to marry these together yet - leaving this for another day and 
another patch set rather than this patch set itself. That was my 
thoguht. I was trying to make an "Easier to extend by just dropping a 
test into a dir" setup here to make maintenance and expansion easier 
over time (and thus encourage testing by having a simple repeatable test 
infra to duplicate). I ended up with a dir per test tool you need to 
build and a driver script in the tests/shell dir. I think this is 
certainly worth considering but perhaps as a separate set of work to 
marry these?

I piggybacked on the existing shell test infra but added a fair few more 
scripts. To do what you suggest I'd need to modify the core shell test 
code to walk subdirs recursively then looking for child scripts. The 
problem is how does perf test's shell handling know about the coresight 
subdir vs the lib subdir? Both contain *.sh shell scripts - the 
difference is the ones in lib are not executable. Is this sufficiently 
different? I could also open them to check the have #!/bin/... as the 
first line. Hardcoding just a single coresight subdir just feels wrong 
and hacky to me, thus the generic recursion solution I suggest here.

I can definitely see how extending to subdirs would make supporting 
testing cleaner and divide things into their own domains (dirs).

> Thanks,
> Leo
> 
>> diff --git a/tools/perf/tests/shell/coresight_memcpy_thread_16k_10.sh b/tools/perf/tests/shell/coresight_memcpy_thread_16k_10.sh
>> new file mode 100755
>> index 000000000000..8972af835016
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight_memcpy_thread_16k_10.sh
>> @@ -0,0 +1,18 @@
>> +#!/bin/sh -e
>> +# Coresight / Memcpy 16k 10 Threads
>> +
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +TEST="memcpy_thread"
>> +. $(dirname $0)/lib/coresight.sh
>> +ARGS="16 10 1"
>> +DATV="16k_10"
>> +DATA="$DATD/perf-$TEST-$DATV.data"
>> +
>> +perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS
>> +
>> +perf_dump_aux_verify "$DATA" 10 10 10
>> +
>> +err=$?
>> +exit $err
>> diff --git a/tools/perf/tests/shell/coresight_thread_loop_check_tid_10.sh b/tools/perf/tests/shell/coresight_thread_loop_check_tid_10.sh
>> new file mode 100755
>> index 000000000000..5b468901f89b
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight_thread_loop_check_tid_10.sh
>> @@ -0,0 +1,19 @@
>> +#!/bin/sh -e
>> +# Coresight / Thread Loop 10 Threads - Check TID
>> +
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +TEST="thread_loop"
>> +. $(dirname $0)/lib/coresight.sh
>> +ARGS="10 1"
>> +DATV="check-tid-10th"
>> +DATA="$DATD/perf-$TEST-$DATV.data"
>> +STDO="$DATD/perf-$TEST-$DATV.stdout"
>> +
>> +SHOW_TID=1 perf record -s $PERFRECOPT -o "$DATA" "$BIN" $ARGS > $STDO
>> +
>> +perf_dump_aux_tid_verify "$DATA" "$STDO"
>> +
>> +err=$?
>> +exit $err
>> diff --git a/tools/perf/tests/shell/coresight_thread_loop_check_tid_2.sh b/tools/perf/tests/shell/coresight_thread_loop_check_tid_2.sh
>> new file mode 100755
>> index 000000000000..f8b7abd3aa03
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight_thread_loop_check_tid_2.sh
>> @@ -0,0 +1,19 @@
>> +#!/bin/sh -e
>> +# Coresight / Thread Loop 2 Threads - Check TID
>> +
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +TEST="thread_loop"
>> +. $(dirname $0)/lib/coresight.sh
>> +ARGS="2 20"
>> +DATV="check-tid-2th"
>> +DATA="$DATD/perf-$TEST-$DATV.data"
>> +STDO="$DATD/perf-$TEST-$DATV.stdout"
>> +
>> +SHOW_TID=1 perf record -s $PERFRECOPT -o "$DATA" "$BIN" $ARGS > $STDO
>> +
>> +perf_dump_aux_tid_verify "$DATA" "$STDO"
>> +
>> +err=$?
>> +exit $err
>> diff --git a/tools/perf/tests/shell/coresight_unroll_loop_thread_10.sh b/tools/perf/tests/shell/coresight_unroll_loop_thread_10.sh
>> new file mode 100755
>> index 000000000000..c985dfb025c2
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/coresight_unroll_loop_thread_10.sh
>> @@ -0,0 +1,18 @@
>> +#!/bin/sh -e
>> +# Coresight / Unroll Loop Thread 10
>> +
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +TEST="unroll_loop_thread"
>> +. $(dirname $0)/lib/coresight.sh
>> +ARGS="10"
>> +DATV="10"
>> +DATA="$DATD/perf-$TEST-$DATV.data"
>> +
>> +perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS
>> +
>> +perf_dump_aux_verify "$DATA" 10 10 10
>> +
>> +err=$?
>> +exit $err
>> diff --git a/tools/perf/tests/shell/lib/coresight.sh b/tools/perf/tests/shell/lib/coresight.sh
>> new file mode 100644
>> index 000000000000..6a611b073f02
>> --- /dev/null
>> +++ b/tools/perf/tests/shell/lib/coresight.sh
>> @@ -0,0 +1,130 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
>> +
>> +# This is sourced from a driver script so no need for #!/bin... etc. at the
>> +# top - the assumption below is that it runs as part of sourcing after the
>> +# test sets up some basic env vars to say what it is.
>> +
>> +# perf record options for the perf tests to use
>> +PERFRECMEM="-m ,128M"
>> +PERFRECOPT="$PERFRECMEM -e cs_etm//u"
>> +
>> +# These tests need to be run as root or coresight won't allow large buffers
>> +# and will not collect proper data
>> +UID=`id -u`
>> +if test "$UID" -ne 0; then
>> +	echo "Not running as root... skip"
>> +	exit 2
>> +fi
>> +
>> +TOOLS=$(dirname $0)
>> +DIR="$TOOLS/coresight/$TEST"
>> +BIN="$DIR/$TEST"
>> +# If the test tool/binary does not exist and is executable then skip the test
>> +if ! test -x "$BIN"; then exit 2; fi
>> +DATD="."
>> +# If the data dir env is set then make the data dir use that instead of ./
>> +if test -n "$PERF_TEST_CORESIGHT_DATADIR"; then
>> +	DATD="$PERF_TEST_CORESIGHT_DATADIR";
>> +fi
>> +# If the stat dir env is set then make the data dir use that instead of ./
>> +STATD="."
>> +if test -n "$PERF_TEST_CORESIGHT_STATDIR"; then
>> +	STATD="$PERF_TEST_CORESIGHT_STATDIR";
>> +fi
>> +
>> +# Called if the test fails - error code 2
>> +err() {
>> +	echo "$1"
>> +	exit 1
>> +}
>> +
>> +# Check that some statistics from our perf
>> +check_val_min() {
>> +	STATF="$4"
>> +	if test "$2" -lt "$3"; then
>> +		echo ", FAILED" >> "$STATF"
>> +		err "Sanity check number of $1 is too low ($2 < $3)"
>> +	fi
>> +}
>> +
>> +perf_dump_aux_verify() {
>> +	# Some basic checking that the AUX chunk contains some sensible data
>> +	# to see that we are recording something and at least a minimum
>> +	# amount of it. We should almost always see F3 atoms in just about
>> +	# anything but certainly we will see some trace info and async atom
>> +	# chunks.
>> +	DUMP="$DATD/perf-tmp-aux-dump.txt"
>> +	perf report --stdio --dump -i "$1" | \
>> +		grep -o -e I_ATOM_F3 -e I_ASYNC -e I_TRACE_INFO > "$DUMP"
>> +	# Simply count how many of these atoms we find to see that we are
>> +	# producing a reasonable amount of data - exact checks are not sane
>> +	# as this is a lossy  process where we may lose some blocks and the
>> +	# compiler may produce different code depending on the compiler and
>> +	# optimization options, so this is rough  just to see if we're
>> +	# either missing almost all the data or all of it
>> +	ATOM_F3_NUM=`grep I_ATOM_F3 "$DUMP" | wc -l`
>> +	ATOM_ASYNC_NUM=`grep I_ASYNC "$DUMP" | wc -l`
>> +	ATOM_TRACE_INFO_NUM=`grep I_TRACE_INFO "$DUMP" | wc -l`
>> +	rm -f "$DUMP"
>> +
>> +	# Arguments provide minimums for a pass
>> +	CHECK_F3_MIN="$2"
>> +	CHECK_ASYNC_MIN="$3"
>> +	CHECK_TRACE_INFO_MIN="$4"
>> +
>> +	# Write out statistics, so over time you can track results to see if
>> +	# there is a pattern - for example we have less "noisy" results that
>> +	# produce more consistent amounts of data each run, to see if over
>> +	# time any techinques to  minimize data loss are having an effect or
>> +	# not
>> +	STATF="$STATD/stats-$TEST-$DATV.csv"
>> +	if ! test -f "$STATF"; then
>> +		echo "ATOM F3 Count, Minimum, ATOM ASYNC Count, Minimum, TRACE INFO Count, Minimum" > "$STATF"
>> +	fi
>> +	echo -n "$ATOM_F3_NUM, $CHECK_F3_MIN, $ATOM_ASYNC_NUM, $CHECK_ASYNC_MIN, $ATOM_TRACE_INFO_NUM, $CHECK_TRACE_INFO_MIN" >> "$STATF"
>> +
>> +	# Actually check to see if we passed or failed.
>> +	check_val_min "ATOM_F3" "$ATOM_F3_NUM" "$CHECK_F3_MIN" "$STATF"
>> +	check_val_min "ASYNC" "$ATOM_ASYNC_NUM" "$CHECK_ASYNC_MIN" "$STATF"
>> +	check_val_min "TRACE_INFO" "$ATOM_TRACE_INFO_NUM" "$CHECK_TRACE_INFO_MIN" "$STATF"
>> +	echo ", Ok" >> "$STATF"
>> +}
>> +
>> +perf_dump_aux_tid_verify() {
>> +	# Specifically crafted test will produce a list of Tread ID's to
>> +	# stdout that need to be checked to  see that they have had trace
>> +	# info collected in AUX blocks in the perf data. This will go
>> +	# through all the TID's that are listed as CID=0xabcdef and see
>> +	# that all the Thread IDs the test tool reports are  in the perf
>> +	# data AUX chunks
>> +
>> +	# The TID test tools will print a TID per stdout line that are being
>> +	# tested
>> +	TIDS=`cat "$2"`
>> +	# Scan the perf report to find the TIDs that are actually CID in hex
>> +	# and build a list of the ones found
>> +	FOUND_TIDS=`perf report --stdio --dump -i "$1" | \
>> +			grep -o "CID=0x[0-9a-z]\+" | sed 's/CID=//g' | \
>> +			uniq | sort | uniq`
>> +
>> +	# Iterate over the list of TIDs that the test says it has and find
>> +	# them in the TIDs found in the perf report
>> +	MISSING=""
>> +	for TID2 in $TIDS; do
>> +		FOUND=""
>> +		for TIDHEX in $FOUND_TIDS; do
>> +			TID=`printf "%i" $TIDHEX`
>> +			if test "$TID" -eq "$TID2"; then
>> +				FOUND="y"
>> +				break
>> +			fi
>> +		done
>> +		if test -z "$FOUND"; then
>> +			MISSING="$MISSING $TID"
>> +		fi
>> +	done
>> +	if test -n "$MISSING"; then
>> +		err "Thread IDs $MISSING not found in perf AUX data"
>> +	fi
>> +}
>> -- 
>> 2.32.0
>>