Re: git-rev-list: "--bisect" flag

From: Linus Torvalds <torvalds@osdl.org>
Date: Jun 19, 2005, 05:30 UTC
Message-ID: <Pine.LNX.4.58.0506182218180.2268@ppc970.osdl.org>
In-Reply-To: <Pine.LNX.4.62.0506182204350.11617@qynat.qvtvafvgr.pbz>

On Sat, 18 Jun 2005, David Lang wrote:

> 
> if it takes you about as long to type the command (and scan it to make 
> sure you didn't mistype it) as it does to execute you don't have a 
> performance problem :-)

Yeah, well, in all honesty, I haven't actually verified that my bisection gives the right answer.

I verified "visually" that it does something half-way sane with this:

  git-rev-list --bisect HEAD ^v2.6.12-rc2 > .git/refs/tags/bisect-1
  git-rev-list --bisect HEAD ^v2.6.12-rc2 ^bisect-1 > .git/refs/tags/bisect-2
  git-rev-list --bisect HEAD ^v2.6.12-rc2 ^bisect-1 ^bisect-2 > .git/refs/tags/bisect-3
  git-rev-list --bisect HEAD ^v2.6.12-rc2 ^bisect-1 ^bisect-2 ^bisect-3 > .git/refs/tags/bisect-4
  git-rev-list --bisect HEAD ^v2.6.12-rc2 ^bisect-1 ^bisect-2 ^bisect-3 ^bisect-4 > .git/refs/tags/bisect-5
  gitk

and it looked sane (ie "bisect-1" should show up as a tag about half-way, and the others should get progressively closer to the HEAD). But when I now tried it again (I did the above originally with plain 2.6.12), I get errors from "gitk":

	ERROR: none of the pending commits can be done yet:
	  bd6ae2f6d61da0f90c6b66e9a4ab6c53ef8c159a
	  2512809255d018744fe6c2f5e996c83769846c07
	  88d7bd8cb9eb8d64bf7997600b0d64f7834047c5
	  b3214970abbe983cd89842ae24ea00e21bba79f6

which looks like the current kernel overflows gitk some way (there's suddenly a lot more parallellism, since there were a number of merges that were pending, waiting for the 2.6.12 release).

		Linus