kernel/git/next/linux-next.git/tools/perf/util/cs-etm.h, branch master

perf cs-etm: Queue context packets for frontend

2026-06-10T21:55:48+00:00

PE_CONTEXT elements update the context ID and exception level, but the decoder may still have prior packets cached for frontend processing. Updating the context immediately in the decoder backend can make those cached packets get consumed with the wrong thread or EL state. Add a CS_ETM_CONTEXT packet carrying the TID and EL to the frontend, this keeps context changes ordered with the rest of the packet stream and avoids mismatches when synthesizing samples from cached packets. Separate the memory access function into one for the frontend and one for decoding. The frontend also needs memory access to attach the instruction to samples. Because the frontend does memory access for both previous and current packets, change all the frontend memory access function signatures to take both a tidq and packet. But backend always uses the current backend EL and thread from the tidq. Treat context packets as a boundary for branch sample generation and remove tidq->prev_packet_thread because it's not possible to branch to a different thread, so only tracking the current thread is required for sample generation. Fixes: e573e978fb12e160 ("perf cs-etm: Inject capabilitity for CoreSight traces") Reported-by: Amir Ayupov Closes: https://lore.kernel.org/linux-perf-users/20260515021135.1729028-1-aaupov@meta.com/ Co-authored-by: James Clark Signed-off-by: Leo Yan Cc: Ian Rogers Cc: Jiri Olsa Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Cc: Mike Leach Cc: Namhyung Kim Cc: Paschalis Mpeis Cc: Robert Walker Cc: Shuah Khan Cc: Suzuki Poulouse Signed-off-by: James Clark Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Finish removal of ETM_OPT_*

2026-03-10T12:50:44+00:00

These #defines have been removed from the kernel headers in favour of the string based PMU format attributes. Usages were previously removed from the recording side of cs-etm in Perf. Finish the removal by removing usages from the decode side too. It's a straight replacement of the old #defines with the new register bit definitions. Except cs_etm__setup_timeless_decoding() which wasn't looking at the saved metadata and was instead hard coding an access to 'attr.config'. This was vulnerable to the same issue of .config being moved to .config2 etc that the original removal of ETM_OPT_* tried to fix. So fix that too. Signed-off-by: James Clark Tested-by: Leo Yan Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf: cs-etm: Create decoders based on the trace ID mappings

2024-08-29T18:55:24+00:00

Now that each queue has a unique set of trace ID mappings, use this list to create the decoders. In unformatted mode just add a single mapping so only one decoder is made. Previously each queue would have a decoder created for each traced CPU on the system but this won't work anymore because CPUs can have overlapping trace IDs. This also means that the CORESIGHT_TRACE_ID_UNUSED_FLAG isn't needed any more. If mappings aren't added then decoders aren't created, rather than needing a flag to suppress creation. Reviewed-by: Mike Leach Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Torgue Cc: Anshuman Khandual Cc: Ganapatrao Kulkarni Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Maxime Coquelin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Link: https://lore.kernel.org/r/20240722101202.26915-5-james.clark@linaro.org Signed-off-by: James Clark Signed-off-by: Arnaldo Carvalho de Melo

perf: cs-etm: Move traceid_list to each queue

2024-08-29T18:54:40+00:00

The global list won't work for per-sink trace ID allocations, so put a list in each queue where the IDs will be unique to that queue. To keep the same behavior as before, for version 0 of the HW_ID packets, copy all the HW_ID mappings into all queues. This change doesn't effect the decoders, only trace ID lookups on the Perf side. The decoders are still created with global mappings which will be fixed in a later commit. Reviewed-by: Mike Leach Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Torgue Cc: Anshuman Khandual Cc: Ganapatrao Kulkarni Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Maxime Coquelin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Link: https://lore.kernel.org/r/20240722101202.26915-4-james.clark@linaro.org Signed-off-by: James Clark Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Lazily compute default config

2023-10-17T19:40:50+00:00

The default config is computed during creation of the PMU and may do things like scanning sysfs, when the PMU may just be used as part of scanning. Change default_config to perf_event_attr_init_default, a callback that is used when a default config needs initializing. This avoids holding onto the memory for a perf_event_attr and copying. On a tigerlake laptop running the pmu-scan benchmark: Before: Running 'internals/pmu-scan' benchmark: Computing performance of sysfs PMU event scan for 100 times Average core PMU scanning took: 28.780 usec (+- 0.503 usec) Average PMU scanning took: 283.480 usec (+- 18.471 usec) Number of openat syscalls: 30,227 After: Running 'internals/pmu-scan' benchmark: Computing performance of sysfs PMU event scan for 100 times Average core PMU scanning took: 27.880 usec (+- 0.169 usec) Average PMU scanning took: 245.260 usec (+- 15.758 usec) Number of openat syscalls: 28,914 Over 3 runs it is a nearly 12% reduction in execution time and a 4.3% of openat calls. Signed-off-by: Ian Rogers Reviewed-by: Adrian Hunter Cc: Ravi Bangoria Cc: James Clark Cc: Suzuki K Poulose Cc: Yang Jihong Cc: Will Deacon Cc: Leo Yan Cc: Mike Leach Cc: Jing Zhang Cc: Kajol Jain Cc: Thomas Richter Cc: Kan Liang Cc: John Garry Cc: linux-arm-kernel@lists.infradead.org Cc: coresight@lists.linaro.org Link: https://lore.kernel.org/r/20231012175645.1849503-8-irogers@google.com Signed-off-by: Namhyung Kim

perf cs-etm: Track exception level

2023-06-12T21:18:13+00:00

Currently we assume all trace belongs to the host machine so when the decoder should be looking at the guest kernel maps it can crash because it looks at the host ones instead. Avoid one scenario (guest kernel running at EL1) by assigning the default guest machine to this trace. For userspace trace it's still not possible to determine guest vs host, but the PIDs should help in this case. Committer notes: Fixed up conflict with: perf addr_location: Add init/exit/copy functions That was only on tmp.perf-tools-next. Reviewed-by: Leo Yan Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230612111403.100613-5-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Make PID format accessible from struct cs_etm_auxtrace

2023-06-12T21:18:13+00:00

To avoid every user of PID format having to use their own static local variable, cache it on initialisation and change the accessor to take struct cs_etm_auxtrace. Reviewed-by: Leo Yan Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230612111403.100613-4-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Copy kernel coresight-pmu.h header

2023-05-26T19:03:27+00:00

Copy the kernel version of the header to fix the header diff build warning. Some new definitions were only added to the tools side header, but these are only used in Perf so move them to a different header. Signed-off-by: James Clark Reviewed-by: Mike Leach Link: https://lore.kernel.org/r/20230522102604.1081416-1-james.clark@arm.com Cc: Mark Rutland Cc: Suzuki K Poulose Cc: Ian Rogers Cc: Peter Zijlstra Cc: Adrian Hunter Cc: acme@kernel.org Cc: Jiri Olsa Cc: Namhyung Kim Cc: Will Deacon Cc: Leo Yan Cc: Alexander Shishkin Cc: linux-arm-kernel@lists.infradead.org Cc: coresight@lists.linaro.org Cc: siyanteng@loongson.cn Cc: John Garry Cc: Ingo Molnar Cc: linux-kernel@vger.kernel.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Use bool type for boolean values

2023-04-24T17:42:20+00:00

Using u8 for boolean values makes the code a bit more difficult to read so be more explicit by using bool. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Denis Nikitin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mathieu Poirier Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Cc: Yang Shi Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230424134748.228137-7-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Allow user to override timestamp and contextid settings

2023-04-24T17:42:20+00:00

Timestamps and context tracking are automatically enabled in per-core mode and it's impossible to override this. Use the new utility function to set them conditionally. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Denis Nikitin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mathieu Poirier Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Cc: Yang Shi Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230424134748.228137-6-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo