Re: Article about "git bisect run" on LWN

From: Ingo Molnar <mingo@elte.hu>
Date: Feb 6, 2009, 01:52 UTC
Message-ID: <20090206015215.GA6261@elte.hu>
In-Reply-To: <20090206014655.GA26807@elte.hu>

* Ingo Molnar <mingo@elte.hu> wrote:

Show 5 quoted lines

> The idea would be to insert 30% redunancy into my bisections automatically 
> - so that i could trust _all_ bisections more - not just the ones i 
> suspect to be non-deterministic. Hence the suggestion to enable lower 
> levels of redundancy like 30%. (but even 10% or 20% might be enough to 
> weed out the most obvious cases)

the other advantage of redundancy that i forgot to mention:

- Sometimes the non-determinism is inserted by a _human_. It happened not
  once that i accidentally mis-judged a testpoint, and the bisection ran
  afoul. Only 4-5 steps later do i suspect that something is wrong: that i 
  get an unlikely series of good,good,good,good,good or bad,bad,bad,bad,bad 
  testpoint qualities.

So for manual bisection, redundancy can be a big time-saver. If i mess up a bisection point then say 50% redundancy can still point out my stupidity with a high likelyhood.

In fact if Git sees an unlikely series of same-quality bisection points, it could artificially insert a test to around the last-different test point, to test the theory of a messed up bisection.

	Ingo