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-v4-0-44f9fb...
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-c39294...
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-v2-0-85b5ce...
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-ebd602...
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