After patching linux perf. This script collects creates a coverage file (e.g.,
for linpack) which can be used for fdo.
gcov=linpack-x86.gcov
MAKE='make'
# x86
x86() {
CC=/usr/bin/gcc
CXX=/usr/bin/g++
export CFLAGS="-Ofast -g3 -static"
export CPPFLAGS=$CFLAGS
$MAKE -C $SRC/SingleSource/Benchmarks/Linpack clean
$MAKE -C $SRC/SingleSource/Benchmarks/Linpack -k TEST=simple TARGET_LLVMGCC=$CC
TARGET_CXX=$CXX LLI_OPTFLAGS= TARGET_CC=$CC TARGET_LLVMGXX=$CXX
CC_UNDER_TEST_IS_GCC=1 TARGET_FLAGS= USE_REFERENCE_OUTPUT=1
CC_UNDER_TEST_TARGET_IS_AARCH64=1 OPTFLAGS= LLC_OPTFLAGS= ENABLE_OPTIMIZED=1
ARCH=x86_64 ENABLE_HASHED_PROGRAM_OUTPUT=1 DISABLE_JIT=1
perfdata=autofdo-linpack/perf-x86.data
perf record -b -e branch-instructions -o $perfdata
$SRC/SingleSource/Benchmarks/Linpack/Output/linpack-pc.simple
autofdo/usr/bin/create_gcov
--binary=$SRC/SingleSource/Benchmarks/Linpack/Output/linpack-pc.simple
--profile=$perfdata --gcov=$gcov
}
hth,
-Aditya
----------------------------------------
> From: a...@firstfloor.org
> To: i.palac...@samsung.com
> CC: dnovi...@google.com; gcc@gcc.gnu.org; davi...@google.com; hubi...@ucw.cz;
> seb...@gmail.com; de...@google.com; v.bari...@samsung.com
> Subject: Re: AutoFDO profile toolchain is open-sourced
> Date: Tue, 21 Apr 2015 07:25:10 -0700
>
> Ilya Palachev <i.palac...@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
>
> --
> a...@linux.intel.com -- Speaking for myself only
