Re: [PATCH] perf-lib: remove old result files before running tests

From: Thomas Gummerer <t.gummerer@gmail.com>
Date: Nov 20, 2019, 08:00 UTC
Message-ID: <20191120080003.GA38901@cat>
In-Reply-To: <xmqq5zjfchix.fsf@gitster-ct.c.googlers.com>

On 11/20, Junio C Hamano wrote:

Show 25 quoted lines

> Thomas Gummerer <t.gummerer@gmail.com> writes:
> 
> > @@ -178,10 +178,11 @@ test_wrapper_ () {
> >  	export test_prereq
> >  	if ! test_skip "$@"
> >  	then
> 
> > -		base=$(basename "$0" .sh)
> 
> So we used to use $base to hold the number and the filename here
> 
> > -		echo "$test_count" >>"$perf_results_dir"/$base.subtests
> > -		echo "$1" >"$perf_results_dir"/$base.$test_count.descr
> >  		base="$perf_results_dir"/"$PERF_RESULTS_PREFIX$(basename "$0" .sh)"."$test_count"
> 
> and then redefined it to be the results-prefix specific one.
> 
> 
> > +		rm -f "$base".*
> 
> you now remove those results-prefix specific one for the $test_count
> (I guess that is as specific you can go) before writing the count
> and the description.  
> 
> So this "rm -f" is a no-op when perf-results-prefix is not empty?

No, not quite. It is a no-op the first time a particular test runs for a specific prefix. The prefix is usually set by the 't/perf/run' script, and indicates the revision that is tested.

So if we were running for example

    ./run deadbeef... p0001-rev-list.sh

we'd have a file 'test-results/build_deadbeef....p0001-rev-list.1.times' in the t/perf directory.

Now we add a 'test_size' test before the first 'test_perf' test, and run the tests again. After this run we'd still have that original file from the test results from the previous run, as well as a 'test-results/build_deadbeef....p0001-rev-list.1.size'.

This duplicate file at the matching "$base" is what we want to avoid. The "rm -f" above would remove 'test-results/build_deadbeef....p0001-rev-list.1.times' so we now only have the '.size' file left, and 'aggregate.perl' gives us the right result.

Show 5 quoted lines

> > +		no_prefix_base="$perf_results_dir"/$(basename "$0" .sh)
> > +		echo "$test_count" >>$no_prefix_base.subtests
> > +		echo "$1" >$no_prefix_base.$test_count.descr
> >  		"$test_wrapper_func_" "$@"
> >  	fi