On Sun, 22 Mar 2020 at 00:24, Peng Fan peng.fan@nxp.com wrote:
Hi All,
I follow this guide to do test on i.MX8MP, https://elinux.org/images/b/b3/Hardware_Assisted_Tracing_on_ARM.pdf
I could see dump with perf report --dump (attached), but when I use perf report --stdio, I met Error: The perf.data data has no samples! # To display the perf.data header info, please use --header/--header-only options. #
The perf I use to dump data is not compiled with CORESIGHT support, but the host perf has been compiled with CORESIGHT support. Do you know what might cause this issue?
Please use the latest kernel release. The instructions you are following are very old - these here [1] are much better. I doubt this is the underlying problem but perf needs to be compiled with coresight support in order to properly handle coresight trace data. As I requested during our previous interaction and something Leo has also pointed out, supporting people without the kernel version and some insight on the HW is next to impossible.
Mathieu
[1]. https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md
Thanks, Peng.