Re: [PATCH V5 0/9] perf: Driver specific configuration for PMU

From: Alexander Shishkin
Date: Mon Aug 22 2016 - 11:16:05 EST


Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> writes:

> 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/@sink=20070000.etr/u --per-thread uname

Can't we simply teach perf record to write 1 to that sysfs attribute and
avoid parsing more ascii strings in the kernel? I suspect that would also
take way less code.

Are there any other use cases for this besides specifying @sink for a
ETM?

Regards,
--
Alex