Re: git bisect on multiple cores

From: Christian Couder <chriscool@tuxfamily.org>
Date: Apr 9, 2008, 05:47 UTC
Message-ID: <200804090747.23596.chriscool@tuxfamily.org>
In-Reply-To: <200804090629.29122.chriscool@tuxfamily.org>

Le mercredi 9 avril 2008, Christian Couder a écrit :

Show 26 quoted lines

> Le mardi 8 avril 2008, A B a écrit :
> > git bisect is really cool. I use it for the first time.
> > Just a thought, if you have a multiple core computer, can't you make
> > git build new versions in the background while testing the previuos
> > version? Alright, if you build 2 versions, one of them will never be
> > tested, but you will perhaps save some time by letting it build in the
> > background?
>
> Yes, you can do that.
>
> If you have cloned your repository twice (or more), then you can bisect
> compile and test at the same time in your 3 repositories (or more if you
> really want).
>
> For example if bisecting in one repo asks you to test revision X, then
> you can bisect and then build (and even maybe start testing) in another
> repo assuming revision X is good, and in yet in another one assuming
> revision X is bad.
>
> (In the repo where you assume X is good you use:
>
> "git bisect start CURRENT-BAD X"
>
> and in the third one, where you assume X is bad, you use:
>
> "git bisect start X CURRENT-GOOD")

In fact, you have to give all the good revisions you have, not just the last one. So it should be

"git bisect start CURRENT-BAD X GOOD1 GOOD2 ..."

or

"git bisect start X GOOD1 GOOD2 ..."

instead of the above.

> When you know that X was good then you can kill the build or test
> processes and "git bisect reset" in the repository where you assumed
> wrongly X was bad. You can then assume something else with "git bisect
> start B G" and build and test in this repo again.

Above also you must give all the good ones, so it is:

"git bisect start B G1 G2..."

> In the repo that told you X was good, then you need only to use "git
> bisect good" or "git bisect bad" without building and testing to assume
> something about the revision that should be built and tested.

Regards, Christian.