On Fri, 6 Jul 2018 at 17:38, Kim Phillips [off-list ref] wrote:

On Thu,  5 Jul 2018 16:13:40 -0600
Mathieu Poirier [off-list ref] wrote:

quoted

This set adds the capability to communiate event specific configuration
to the PMU kernel driver using an ioctl().  The functionatlity is made
generic enough for anyone to use but is targeted at the identification
of CoreSight sinks when operating in CPU-wide trace scenarios.

With this series, a --per-thread -less invocation looks like it
succeeds (instead of giving a "failed to mmap with 12 (Cannot allocate
memory)" error):

# perf record -e /cs_etm/@20010000.etf/ sleep 1
[ perf record: Woken up 3 times to write data ]
Warning:
AUX data lost 2 times out of 3!

[ perf record: Captured and wrote 0.182 MB perf.data ]
#

but now perf report - built with libopencsd - is unable to process the
perf.data file:

# perf report --stdio
0x3a0 [0x60]: failed to process type: 1
Error:
failed to process sample
# To display the perf.data header info, please use --header/--header-only options.
#

Right, that's expected since the perf tools patches for CPU-wide trace
scenarios haven't been merged yet.  The real problem is, as you
pointed above, that this patchset should still report an error as full
functionality isn't merged yet.  I will fix that.

Also, a "record -a" invocation also acts like it's working, but Juno
has a hardware limitation where it can't record all cpus concurrently,
right?  So, shouldn't record commands that exceed the h/w's
capabilities error out instead?

To be clear there is no hardware limitation preventing "record -a" to
work properly, just SW.  This patchset is the first step in addressing
the situation.

Thanks,
Mathieu

Thanks,

Kim