Hi Kim,

I've split off this issue from the original thread (keeping the original audience). A bit more investigation this morning shows that on my juno-r1 the issue only occurs if you enable the TPIU. (couldn't use the r2 but I don't think the differences are relevant here).

See below for test run info.

As far as I am aware, the TPIU driver is currently a stub driver - granted it would be better if it failed gracefully and gave a useful error message, but enabling is not useful without external trace capture (and we might expect the external device to enable this - bit of a grey area starting trace by system calls then piping out to external device).

Mike

===All 4 sinks - mmap error ============

mleach@linaro-developer:~/perf-tools$ for i in /sys/bus/coresight/devices/*/enable_sink; do echo $i; done
/sys/bus/coresight/devices/20010000.etf/enable_sink
/sys/bus/coresight/devices/20030000.tpiu/enable_sink
/sys/bus/coresight/devices/20070000.etr/enable_sink
/sys/bus/coresight/devices/20140000.etf/enable_sink
mleach@linaro-developer:~/perf-tools$ for i in /sys/bus/coresight/devices/*/enable_sink; do echo 1 | sudo tee $i; done
1
1
1
1
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
failed to mmap with 12 (Cannot allocate memory)
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
Linux
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.077 MB perf.data ]
=============================

====== etf @ 2001 only - no error ===========

mleach@linaro-developer:~/perf-tools$ echo 1 | sudo tee /sys/bus/coresight/devices/20010000.etf/enable_sink
1
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
Linux
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.077 MB perf.data ]
=============================

======etr @ 2007 only - no error ============

mleach@linaro-developer:~/perf-tools$ echo 1 | sudo tee /sys/bus/coresight/devices/20070000.etr/enable_sink
1
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.076 MB perf.data ]
=============================
mleach@linaro-developer:~/perf-tools$ echo 1 | sudo tee /sys/bus/coresight/devices/20140000.etf/enable_sink
1
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
Linux
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.077 MB perf.data ]
=============================

=====tpiu @ 2003 only - mmap error =================

mleach@linaro-developer:~/perf-tools$ echo 1 | sudo tee /sys/bus/coresight/device/20030000.tpiu/enable_sink
1
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
failed to mmap with 12 (Cannot allocate memory)
mleach@linaro-developer:~/perf-tools$
mleach@linaro-developer:~/perf-tools$ sudo taskset -c 2 ./perf record -e cs_etm/@20070000.etr/u --per-thread taskset -c 2 uname
Linux
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.076 MB perf.data ]
mleach@linaro-developer:~/perf-tools$
=============================