Re: [PATCH v5 00/19] perf cs-etm: Queue context packets for frontend

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Tue, Jun 09, 2026 at 03:40:05PM +0100, James Clark wrote:
> Fix thread tracking when decoding Coresight trace and add a new test for
> it.

The issues found by sashiko seem mild and you can address them in follow
up patches, I think.

So for the benefit of having perf-tools-next available for linux-next
testing and the window is closing soon, so I've merged this, ok?

- Arnaldo
 
> The new test is added as a Perf test workload instead of a custom binary
> with its own build system, but this requires a new feature in Perf test
> to pass in control pipes which can enable and disable events. This
> scopes the recording to just the workload and helps to reduce the amount
> of data recorded in tracing tests.
> 
> With this new feature we can re-write all of the Coresight tests to make
> use of it and remove the remaining binaries which fixes the following
> issues:
> 
>  * They didn't work in out of source builds
>  * A lot of the tests unnecessarily required root and didn't skip
>    without it
>  * They were mainly qualitative tests which didn't look for specific
>    behavior
> 
> Most importantly, the long build and runtime has been reduced. On a
> Radxa Orion O6, unroll_loop_thread.c took 37s to compile which is longer
> than the entire Perf build. Now the build time is negligible and the
> before and after test runtimes for all the Coresight tests are:
> 
>           |   N1SDP   |   Orion O6
>   -----------------------------------
>   Before  |   4m  0s  |    14m 49s
>   After   |      26s  |        56s
>   -----------------------------------
> 
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> Changes in v5:
> - Forgot to include this change:
>   - Test for actual length of expected raw dump (Leo)
> - Link to v4: https://lore.kernel.org/r/20260609-james-cs-context-tracking-fix-v4-0-44f9fb9e5c42@linaro.org
> 
> Changes in v4:
> - Rename workload-ctl to record-ctl and improve docs (Leo)
> - Use new packet argument everywhere in
>   cs_etm__synth_instruction_sample() (Sashiko)
> - Test for actual length of expected raw dump (Leo)
> - Use -fno-inline instead of keyword (Leo)
> - Don't test any brace or call lines in deterministic test
> - Make sure context switch loop test does cleanup on failure (Sashiko)
> - Remove undef int overflows in workloads (Sashiko)
> - Link to v3: https://lore.kernel.org/r/20260603-james-cs-context-tracking-fix-v3-0-c392945d9ed5@linaro.org
> 
> Changes in v3:
> - Minor sashiko comments
>   - Close some more pipes
>   - Fix warning messages
>   - Error handling improvements
> - Pass packet into cs_etm__synth_instruction_sample()
> - Fixup stale comment (Leo)
> - Link to v2: https://lore.kernel.org/r/20260602-james-cs-context-tracking-fix-v2-0-85b5ce6f55c6@linaro.org
> 
> Changes in v2:
> - Add --workload-ctl option to Perf test
> - Re-write all the Coresight tests and speed them up
> - Pass packet to memory access function so frontend can use either the
>   previous or current packet's EL
> - Link to v1: https://lore.kernel.org/r/20260526-james-cs-context-tracking-fix-v1-0-ebd602e18287@linaro.org
> 
> ---
> James Clark (19):
>       perf cs-etm: Queue context packets for frontend
>       perf test: Add workload-ctl option
>       perf test: Add a workload that forces context switches
>       perf test cs-etm: Test process attribution
>       perf test: Add deterministic workload
>       perf test cs-etm: Replace unroll loop thread with deterministic decode test
>       perf test cs-etm: Remove asm_pure_loop test
>       perf test cs-etm: Replace memcpy test with raw dump stress test
>       perf test: Add named_threads workload
>       perf test cs-etm: Test decoding for concurrent threads test
>       perf test cs-etm: Remove duplicate branch tests
>       perf test cs-etm: Skip if not root
>       perf test cs-etm: Reduce snapshot size
>       perf test cs-etm: Speed up basic test
>       perf test cs-etm: Remove unused Coresight workloads
>       perf test cs-etm: Make disassembly test use kcore
>       perf test cs-etm: Add all branch instructions to test
>       perf test cs-etm: Speed up disassembly test
>       perf test cs-etm: Move existing tests to coresight folder
> 
>  Documentation/trace/coresight/coresight-perf.rst   |  78 +------
>  MAINTAINERS                                        |   2 -
>  tools/perf/Documentation/perf-test.txt             |  24 ++-
>  tools/perf/Makefile.perf                           |  14 +-
>  tools/perf/scripts/python/arm-cs-trace-disasm.py   |  20 +-
>  tools/perf/tests/builtin-test.c                    | 187 +++++++++++++++-
>  tools/perf/tests/shell/coresight/Makefile          |  29 ---
>  .../perf/tests/shell/coresight/Makefile.miniconfig |  14 --
>  tools/perf/tests/shell/coresight/asm_pure_loop.sh  |  22 --
>  .../tests/shell/coresight/asm_pure_loop/.gitignore |   1 -
>  .../tests/shell/coresight/asm_pure_loop/Makefile   |  34 ---
>  .../shell/coresight/asm_pure_loop/asm_pure_loop.S  |  30 ---
>  .../tests/shell/coresight/concurrent_threads.sh    |  45 ++++
>  .../tests/shell/coresight/context_switch_thread.sh |  69 ++++++
>  tools/perf/tests/shell/coresight/deterministic.sh  |  72 +++++++
>  .../tests/shell/coresight/memcpy_thread/.gitignore |   1 -
>  .../tests/shell/coresight/memcpy_thread/Makefile   |  33 ---
>  .../shell/coresight/memcpy_thread/memcpy_thread.c  |  80 -------
>  .../tests/shell/coresight/memcpy_thread_16k_10.sh  |  22 --
>  .../perf/tests/shell/coresight/raw_dump_stress.sh  |  65 ++++++
>  .../shell/{ => coresight}/test_arm_coresight.sh    |  43 ++--
>  .../{ => coresight}/test_arm_coresight_disasm.sh   |  23 +-
>  .../tests/shell/coresight/thread_loop/.gitignore   |   1 -
>  .../tests/shell/coresight/thread_loop/Makefile     |  33 ---
>  .../shell/coresight/thread_loop/thread_loop.c      |  85 --------
>  .../shell/coresight/thread_loop_check_tid_10.sh    |  23 --
>  .../shell/coresight/thread_loop_check_tid_2.sh     |  23 --
>  .../shell/coresight/unroll_loop_thread/.gitignore  |   1 -
>  .../shell/coresight/unroll_loop_thread/Makefile    |  33 ---
>  .../unroll_loop_thread/unroll_loop_thread.c        |  75 -------
>  .../tests/shell/coresight/unroll_loop_thread_10.sh |  22 --
>  tools/perf/tests/shell/lib/coresight.sh            | 134 ------------
>  tools/perf/tests/tests.h                           |   3 +
>  tools/perf/tests/workloads/Build                   |   4 +
>  tools/perf/tests/workloads/context_switch_loop.c   | 110 ++++++++++
>  tools/perf/tests/workloads/deterministic.c         |  39 ++++
>  tools/perf/tests/workloads/named_threads.c         | 109 ++++++++++
>  tools/perf/util/cs-etm-decoder/cs-etm-decoder.c    |  21 +-
>  tools/perf/util/cs-etm.c                           | 236 ++++++++++++---------
>  tools/perf/util/cs-etm.h                           |   8 +-
>  40 files changed, 926 insertions(+), 942 deletions(-)
> ---
> base-commit: 351a37f2fda4db668cff8ba12f2992d73dccdaea
> change-id: 20260515-james-cs-context-tracking-fix-754998bae7ed
> 
> Best regards,
> -- 
> James Clark <james.clark@linaro.org>