On 28 August 2016 at 08:18, Jiri Olsa [off-list ref] wrote:

On Thu, Aug 25, 2016 at 02:20:40PM -0600, Mathieu Poirier wrote:

SNIP

quoted

perf record -e some_event/@cfg1, at cfg2=config/ ...

The above are all valid configuration and will see the strings 'cfg1'
and 'cfg2=config' sent to the PMU driver for parsing and interpretation
using the existing ioctl() mechanism.

The primary customers for this feature are the CoreSight drivers where
the selection of a sink (where trace data is accumulated) needs to be
done in a previous, and separated step, from the launching of the perf
command.

As such something that used to be a two-step process:

# echo 1 > /sys/bus/coresight/devices/20070000.etr/enable_sink
# perf record -e cs_etm//u --per-thread  uname

is integrated in a single command:

# perf record -e cs_etm/@20070000.etr/u --per-thread  uname

Thanks,
Mathieu

Changes for V6:
- Using sysFS rather than an ioctl() to communicate command line
  parameters to the CoreSight PMU.

apart from few nits it looks good.. but can't say for patch 2/5 ;-)

Acked-by: Jiri Olsa <jolsa@kernel.org>

Many thanks for taking the time to look at this set - your time is
much appreciated.

thanks,
jirka