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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-06-06 11:50:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-06-06 11:50:47 -0700 |
| commit | c26f4fbd58375bd6ef74f95eb73d61762ad97c59 (patch) | |
| tree | 0bec60c3a022bfe531420265f1b489ee4aaa1eb1 /Documentation/trace | |
| parent | a100922a3855eb35ecd465f1d558546b1e144445 (diff) | |
| parent | 9857af0fcff385c75433f2162c30c62eb912ef6d (diff) | |
Merge tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / iio driver updates from Greg KH:
"Here is the big char/misc/iio and other small driver subsystem pull
request for 6.16-rc1.
Overall, a lot of individual changes, but nothing major, just the
normal constant forward progress of new device support and cleanups to
existing subsystems. Highlights in here are:
- Large IIO driver updates and additions and device tree changes
- Android binder bugfixes and logfile fixes
- mhi driver updates
- comedi driver updates
- counter driver updates and additions
- coresight driver updates and additions
- echo driver removal as there are no in-kernel users of it
- nvmem driver updates
- spmi driver updates
- new amd-sbi driver "subsystem" and drivers added
- rust miscdriver binding documentation fix
- other small driver fixes and updates (uio, w1, acrn, hpet,
xillybus, cardreader drivers, fastrpc and others)
All of these have been in linux-next for quite a while with no
reported problems"
* tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (390 commits)
binder: fix yet another UAF in binder_devices
counter: microchip-tcb-capture: Add watch validation support
dt-bindings: iio: adc: Add ROHM BD79100G
iio: adc: add support for Nuvoton NCT7201
dt-bindings: iio: adc: add NCT7201 ADCs
iio: chemical: Add driver for SEN0322
dt-bindings: trivial-devices: Document SEN0322
iio: adc: ad7768-1: reorganize driver headers
iio: bmp280: zero-init buffer
iio: ssp_sensors: optimalize -> optimize
HID: sensor-hub: Fix typo and improve documentation
iio: admv1013: replace redundant ternary operator with just len
iio: chemical: mhz19b: Fix error code in probe()
iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS
iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS
iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS
iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS
iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS
iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros
iio: make IIO_DMA_MINALIGN minimum of 8 bytes
...
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/coresight/coresight-perf.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/trace/coresight/coresight-perf.rst b/Documentation/trace/coresight/coresight-perf.rst index d087aae7d492..30be89320621 100644 --- a/Documentation/trace/coresight/coresight-perf.rst +++ b/Documentation/trace/coresight/coresight-perf.rst @@ -78,6 +78,37 @@ enabled like:: Please refer to the kernel configuration help for more information. +Fine-grained tracing with AUX pause and resume +---------------------------------------------- + +Arm CoreSight may generate a large amount of hardware trace data, which +will lead to overhead in recording and distract users when reviewing +profiling result. To mitigate the issue of excessive trace data, Perf +provides AUX pause and resume functionality for fine-grained tracing. + +The AUX pause and resume can be triggered by associated events. These +events can be ftrace tracepoints (including static and dynamic +tracepoints) or PMU events (e.g. CPU PMU cycle event). To create a perf +session with AUX pause / resume, three configuration terms are +introduced: + +- "aux-action=start-paused": it is specified for the cs_etm PMU event to + launch in a paused state. +- "aux-action=pause": an associated event is specified with this term + to pause AUX trace. +- "aux-action=resume": an associated event is specified with this term + to resume AUX trace. + +Example for triggering AUX pause and resume with ftrace tracepoints:: + + perf record -e cs_etm/aux-action=start-paused/k,syscalls:sys_enter_openat/aux-action=resume/,syscalls:sys_exit_openat/aux-action=pause/ ls + +Example for triggering AUX pause and resume with PMU event:: + + perf record -a -e cs_etm/aux-action=start-paused/k \ + -e cycles/aux-action=pause,period=10000000/ \ + -e cycles/aux-action=resume,period=1050000/ -- sleep 1 + Perf test - Verify kernel and userspace perf CoreSight work ----------------------------------------------------------- |