Mathieu,

Thanks for that.

On 19/06/18 20:45, Mathieu Poirier wrote:

Good afternoon to all,

For the 4.18 cycle I pushed Suzuki's new ETR driver implementation to GitHub's perf-opencsd repository [1]. It includes support for SG and contiguous mode, all handled automatically without the need for user intervention. I gave it a couple of spin and things work as advertised.

So it's up there now - please try it out in your setup while I review the patches on the public mailing list.

Note that this has no correlation with the support for CPU-wide scenarios patchset I sent out last week.

For people interested in testing it out :

Please note that the scatter-gather mode is disabled by default, unless the DT has the following property in the TMC-ETR :

"arm,scatter-gather"

If you see packet losses, you could tune the buffer sizes to avoid it.

And as you may be aware, you could tune the aux trace buffer size by using :

perf record -m <mmap-size>,<aux-trace-size> ....

and also, you could tune the buffer size used by the ETR by setting :

/sys/.../devices/<tmc-etr-device>/buffer_size

Regards Suzuki