Re: [PATCH 2/7] perf tools: Add util function for overriding user set config values

[James Clark]

On 24/04/2023 18:45, Arnaldo Carvalho de Melo wrote:
> Em Mon, Apr 24, 2023 at 06:36:14PM +0300, Adrian Hunter escreveu:
>> On 24/04/23 16:47, James Clark wrote:
>>> There is some duplicated code to only override config values if they
>>> haven't already been set by the user so make a util function for this.
>>>
>>> Signed-off-by: James Clark <james.clark@xxxxxxx>
>>
>> One minor comment, nevertheless:
>>
>> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> 
> I just moved to  evsel__set_config_if_unset() to util/pmu.c, next to
> some other evsel__ functions to not break the python.so binding, before
> I was getting:
> 
> [acme@quaco perf-tools-next]$ perf test -v python
> Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
>  19: 'import perf' in python                                         :
> --- start ---
> test child forked, pid 500086
> python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf-tools-next/python'); import perf" | '/usr/bin/python3' "
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> ImportError: /tmp/build/perf-tools-next/python/perf.cpython-311-x86_64-linux-gnu.so: undefined symbol: perf_pmu__format_bits
> test child finished with -1
> ---- end ----
> 'import perf' in python: FAILED!
> [acme@quaco perf-tools-next]$
> 
> Please run 'perf test' and 'make -C tools/perf build-test' prior to
> sending pull requests,
> 
> Thanks, applied.
> 

Ah sorry! I ran it from an in source build and got the python import
error so I ignored that test. I see the new error if I run it from
tools/perf instead.

Interestingly with an out of source build it doesn't matter which cwd
you run the Python test from because $OUTPUT is an absolute path.
Normally I do an out of source build, but the Coresight tests don't
currently work with that. Which I will submit another fix for...

I don't know if it's worth getting rid of that edge by making sure
PYTHONPATH is always absolute even for in source builds or if it will
break something else like a make install? It's because of this line:

  -DPYTHONPATH="BUILD_STR($(OUTPUT)python)"

Will make sure that they all pass next time. I also sent a fix for the
build-test target on my platform.

> - Arnaldo
>