Re: [BUG] 2.6.23-rc3 can't see sd partitions on Alpha

From: Ingo Molnar <mingo@elte.hu>
To: Bob Tracy <rct@frus.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	mcree@orcon.net.nz, linux-kernel@vger.kernel.org, rjw@sisk.pl,
	rth@twiddle.net, ink@jurassic.park.msu.ru,
	linux-scsi@vger.kernel.org, kay.sievers@vrfy.org, greg@kroah.com
Subject: Re: [BUG] 2.6.23-rc3 can't see sd partitions on Alpha
Date: Fri, 7 Dec 2007 12:40:48 +0100	[thread overview]
Message-ID: <20071207114048.GB14598@elte.hu> (raw)
In-Reply-To: <20071207050709.110D2DBA2@gherkin.frus.com>

* Bob Tracy <rct@frus.com> wrote:

> > I'm struggling to see how any of those could have broken block 
> > device mounting on alpha.  Are you sure you bisected right?
> 
> Based on what's in that commit, it *does* appear something went wrong 
> with bisection.  If the implicated commit is the next one in time 
> sequence relative to
> 
> # good: [2f1f53bdc6531696934f6ee7bbdfa2ab4f4f62a3] CRISv10 fasttimer: Scrap INLINE and name timeval_cmp better
> 
> then the test of whether I bisected correctly is as simple as applying 
> the commit and seeing if things break, because I'm running on the 
> kernel corresponding to 2f1f53bdc6531696934f6ee7bbdfa2ab4f4f62a3 right 
> now.  Let me give that a try and I'll report back.  Worst case, I'll 
> have to start over and write off the past four days...

generally it's easier to just go "back in time" and re-try the last 
known "good" and last-known "bad" commit IDs to establish that they are 
indeed correctly identified. if they are not then step back one more in 
the bisection log. No need to spend another 4 days on this, if most of 
the bisection is OK. You can replay a corrected git bisection log 
quickly, by doing:

  git-bisect reset
  git-bisect < bisect.log

	Ingo