Re: [PATCH v11 0/9] fix several inconsistencies with sysfs configuration in etmX

From: Leo Yan

Date: Thu Sep 24 2026 - 11:36:12 EST


On Tue, Sep 15, 2026 at 12:34:35PM +0100, Yeoreum Yun wrote:

> To resolve these inconsistencies, the configuration should be separated into:
>
> - active_config, which is applied configuration for the current session
> - config, which stores the settings configured via sysfs.
>
> and apply configuration from configfs after taking a mode.

I did the following tests on this series:

1) Perf test on Orion6 board:

# ./perf test coresight
142: CoreSight synthesized callchain : Ok
143: CoreSight concurrent threads : Ok
144: CoreSight context switch thread attribution : Ok
145: CoreSight deterministic workload decode : Ok
146: CoreSight raw dump stress : Ok
147: Check Arm CoreSight trace data recording and synthesized samples : FAILED!
148: Check Arm CoreSight disassembly script completes without errors : Ok

Test 147 has a known issue with per-thread mode. The failure was already
observed before this series.

2) Strobe mode test:

# echo 5000 > /sys/kernel/config/cs-syscfg/features/strobing/params/window/value

# echo 0 > /sys/kernel/config/cs-syscfg/features/strobing/params/period/value
# perf record -e cs_etm/autofdo,timestamp=0/u -m,128M -- perf test -w brstack 3000000
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 36.301 MB perf.data ]

# echo 1 > /sys/kernel/config/cs-syscfg/features/strobing/params/period/value
# perf record -e cs_etm/autofdo,timestamp=0/u -m,128M -- perf test -w brstack 3000000
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 18.361 MB perf.data ]

# echo 2 > /sys/kernel/config/cs-syscfg/features/strobing/params/period/value
# perf record -e cs_etm/autofdo,timestamp=0/u -m,128M -- perf test -w brstack 3000000
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 12.246 MB perf.data ]

# echo 3 > /sys/kernel/config/cs-syscfg/features/strobing/params/period/value
# perf record -e cs_etm/autofdo,timestamp=0/u -m,128M -- perf test -w brstack 3000000
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 9.197 MB perf.data ]

The captured trace sizes maintain the expected proportional relationship
with the period values.

3) I verified the series on Juno-r2 baord with insmod and rmmod, and
CPU PM, and did not see any regression.

Maybe it'd be good to send a new version addressing Mike's comments.
Based on the test results, you can add my test tags:

Tested-by: Leo Yan <leo.yan@xxxxxxx>