Re: [PATCH/RFC/GSoC 01/17] perf: introduce performance tests for git-rebase

From: Paul Tan <pyokagan@gmail.com>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Git List <git@vger.kernel.org>,
	Junio C Hamano <gitster@pobox.com>,
	Duy Nguyen <pclouds@gmail.com>,
	Stefan Beller <sbeller@google.com>,
	Sam Halliday <sam.halliday@gmail.com>
Subject: Re: [PATCH/RFC/GSoC 01/17] perf: introduce performance tests for git-rebase
Date: Wed, 16 Mar 2016 19:51:53 +0800	[thread overview]
Message-ID: <CACRoPnS=qg=a3xYKHyk-7E2HN5HhTimGirZcwL8hMa0xLY6KdA@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1603160855390.4690@virtualbox>

Hi Dscho,

On Wed, Mar 16, 2016 at 3:58 PM, Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> Hi Paul,
>
> On Sat, 12 Mar 2016, Paul Tan wrote:
>
>> diff --git a/t/perf/p3404-rebase-interactive.sh b/t/perf/p3404-rebase-interactive.sh
>> new file mode 100755
>> index 0000000..aaca105
>> --- /dev/null
>> +++ b/t/perf/p3404-rebase-interactive.sh
>> @@ -0,0 +1,26 @@
>>
>> [...]
>>
>> +test_perf 'rebase -i --onto master^' '
>> +     git checkout perf-topic-branch &&
>> +     git reset --hard perf-topic-branch-initial &&
>> +     GIT_SEQUENCE_EDITOR=: git rebase -i --onto master^ master
>> +'
>
> This measures the performance of checkout && reset && rebase -i. Maybe we
> should only test rebase -i?

test_perf runs the same script multiple times, so we need to reset
--hard at least to undo the changes of the rebase.

I think we can remove the reset if we use rebase -f and rebase onto
the same base, but -f was not implemented in this patch series.

> Also, I would strongly recommend an extra test_commit after reset;
> Otherwise you would only test the logic that verifies that it can simply
> fast-forward instead of cherry-picking.

Or, we could use the -f flag, I think.

Thanks,
Paul