This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: AutoFDO profile toolchain is open-sourced


Ilya Palachev <i.palachev@samsung.com> writes:
>
> But why create_gcov does not inform about that (no branch events were
> found)? It creates empty gcov file and says nothing :(
>
> Moreover, in the mentioned README it is said that perf should also be
> executed with option -e BR_INST_RETIRED:TAKEN.

Standard perf doesn't have a full event list
This assumes a perf patched with the libpfm patch.

Also I suspect it really wants to use PEBS events, so pp should be added.

Alternatively you can use ocperf (from
http://github.com/andikleen/pmu-tools) which is just a wrapper:

ocperf.py record -e br_inst_retired.near_taken:pp -b ... 

or specify the event manually (depending on your CPU, like)

perf record -e
cpu/event=0xc4,umask=0x20,name=br_inst_retired_near_taken,period=400009/pp
-b ...

BTW the biggest problem with autofdo currently is that it is
quite bitrotten and supports only several years old perf.
So all of this above will only work with old distributions,
unless you compile an old perf utility first.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]