git bisect selects commit outside initial bisect range?

git bisect selects commit outside initial bisect range?

[Paweł Sikora]

hi,

i've noticed on kernel 2.6.35.y some weird screen blinking during
e.g. <alt-tab> on kde4 with enabled accelerated desktop effects.

i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
and after few steps git-bisect jumps to commit before v2.6.34.

[~/src/linux/linux-2.6]$ make kernelrelease
2.6.34-rc6-00551-g7a6cb0d

[~/src/linux/linux-2.6]$ git bisect log
git bisect start
# good: [e40152ee1e1c7a63f4777791863215e3faa37a86] Linus 2.6.34
git bisect good e40152ee1e1c7a63f4777791863215e3faa37a86
# bad: [67a3e12b05e055c0415c556a315a3d3eb637e29e] Linux 2.6.35-rc1
git bisect bad 67a3e12b05e055c0415c556a315a3d3eb637e29e
# good: [f8965467f366fd18f01feafb5db10512d7b4422c] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
git bisect good f8965467f366fd18f01feafb5db10512d7b4422c
# bad: [d79df0b1eda0099a22cbcece01ce5e7d222450de] Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6
git bisect bad d79df0b1eda0099a22cbcece01ce5e7d222450de
# good: [ac3ee84c604502240122c47b52f0542ec8774f15] Merge branch 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
git bisect good ac3ee84c604502240122c47b52f0542ec8774f15

is it normal that bisect selects next step outside initial range?

BR,
Pawel.

ps).
please CC me on reply.

Re: git bisect selects commit outside initial bisect range?

[N.P.S. N.P.S.]

Hi,

W dniu 27 września 2010 20:51 użytkownik Paweł Sikora <pluto@agmk.net> napisał:
> hi,
>
> i've noticed on kernel 2.6.35.y some weird screen blinking during
> e.g. <alt-tab> on kde4 with enabled accelerated desktop effects.
>
> i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
> and after few steps git-bisect jumps to commit before v2.6.34.
>
> [~/src/linux/linux-2.6]$ make kernelrelease
> 2.6.34-rc6-00551-g7a6cb0d
>
> [~/src/linux/linux-2.6]$ git bisect log
> git bisect start
> # good: [e40152ee1e1c7a63f4777791863215e3faa37a86] Linus 2.6.34
> git bisect good e40152ee1e1c7a63f4777791863215e3faa37a86
> # bad: [67a3e12b05e055c0415c556a315a3d3eb637e29e] Linux 2.6.35-rc1
> git bisect bad 67a3e12b05e055c0415c556a315a3d3eb637e29e
> # good: [f8965467f366fd18f01feafb5db10512d7b4422c] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
> git bisect good f8965467f366fd18f01feafb5db10512d7b4422c
> # bad: [d79df0b1eda0099a22cbcece01ce5e7d222450de] Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6
> git bisect bad d79df0b1eda0099a22cbcece01ce5e7d222450de
> # good: [ac3ee84c604502240122c47b52f0542ec8774f15] Merge branch 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
> git bisect good ac3ee84c604502240122c47b52f0542ec8774f15
>
> is it normal that bisect selects next step outside initial range?

It seems to me that it could happen - there are many merges of many
branches of the code - some of them may have really old commits.

>
> BR,
> Pawel.
>
> ps).
> please CC me on reply.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>



-- 
Slawa!
N.P.S.

Re: git bisect selects commit outside initial bisect range?

[Andreas Schwab]

Paweł Sikora <pluto@agmk.net> writes:

> i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
> and after few steps git-bisect jumps to commit before v2.6.34.
>
> [~/src/linux/linux-2.6]$ make kernelrelease
> 2.6.34-rc6-00551-g7a6cb0d
>
> is it normal that bisect selects next step outside initial range?

It's not outside the range:

$ git rev-list v2.6.34..v2.6.35-rc1 | grep ^7a6cb0d
7a6cb0d5497418599d2125b670926b75e673861c

7a6cb0d is a commit in a branch reachable from v2.6.35-rc1 but not from
v2.6.34.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: git bisect selects commit outside initial bisect range?

[Valdis.Kletnieks]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=us-ascii, Size: 1315 bytes --]

On Mon, 27 Sep 2010 22:29:13 +0200, Andreas Schwab said:
> Paweł Sikora <pluto@agmk.net> writes:
> 
> > i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
> > and after few steps git-bisect jumps to commit before v2.6.34.
> >
> > [~/src/linux/linux-2.6]$ make kernelrelease
> > 2.6.34-rc6-00551-g7a6cb0d
> >
> > is it normal that bisect selects next step outside initial range?
> 
> It's not outside the range:
> 
> $ git rev-list v2.6.34..v2.6.35-rc1 | grep ^7a6cb0d
> 7a6cb0d5497418599d2125b670926b75e673861c
> 
> 7a6cb0d is a commit in a branch reachable from v2.6.35-rc1 but not from
> v2.6.34.

I think he was confused because that commit is in an section of the tree
that was committed to a maintainer tree before 2.6.34 - so when he boots
the resulting kernel it says 2.6.33-rc3-mumble or similar.  I know it threw
me for a loop the first few times it happened.

Pawel: What's happened is you're looking at a commit that got into a maintainer
tree *before* 2.6.34 came out (so the top-level Makefile *at that time in that
tree* said 2.6.33-mumble or something), but the maintainer fed it into Linus's
tree in the merge window *after* 2.6.34 shipped.  Yes, it's bizarre, but that's
how git deals with it.  If you look at the graph produced by 'git bisect
visualize' it makes a bit more sense.


[-- Attachment #2: Type: application/pgp-signature, Size: 227 bytes --]

Re: git bisect selects commit outside initial bisect range?

[Paolo Ornati]

On Mon, 27 Sep 2010 20:51:33 +0200
Paweł Sikora <pluto@agmk.net> wrote:

> i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
> and after few steps git-bisect jumps to commit before v2.6.34.

Here there is a "graphical" explaination:

http://kerneltrap.org/mailarchive/linux-kernel/2010/9/1/4614187

Bye,

-- 
	Paolo Ornati
	Linux 2.6.35.4 on x86_64

Re: git bisect selects commit outside initial bisect range?

[Paweł Sikora]

On Monday 27 September 2010 23:51:47 Valdis.Kletnieks@vt.edu wrote:
> On Mon, 27 Sep 2010 22:29:13 +0200, Andreas Schwab said:
> > Paweł Sikora <pluto@agmk.net> writes:
> > 
> > > i've started git bisect between good-v2.6.34 and bad-v2.6.35-rc1
> > > and after few steps git-bisect jumps to commit before v2.6.34.
> > >
> > > [~/src/linux/linux-2.6]$ make kernelrelease
> > > 2.6.34-rc6-00551-g7a6cb0d
> > >
> > > is it normal that bisect selects next step outside initial range?
> > 
> > It's not outside the range:
> > 
> > $ git rev-list v2.6.34..v2.6.35-rc1 | grep ^7a6cb0d
> > 7a6cb0d5497418599d2125b670926b75e673861c
> > 
> > 7a6cb0d is a commit in a branch reachable from v2.6.35-rc1 but not from
> > v2.6.34.
> 
> I think he was confused because that commit is in an section of the tree
> that was committed to a maintainer tree before 2.6.34 - so when he boots
> the resulting kernel it says 2.6.33-rc3-mumble or similar.  I know it threw
> me for a loop the first few times it happened.
> 
> Pawel: What's happened is you're looking at a commit that got into a maintainer
> tree *before* 2.6.34 came out (so the top-level Makefile *at that time in that
> tree* said 2.6.33-mumble or something), but the maintainer fed it into Linus's
> tree in the merge window *after* 2.6.34 shipped.  Yes, it's bizarre, but that's
> how git deals with it.  If you look at the graph produced by 'git bisect
> visualize' it makes a bit more sense.

thank you very much for explanation!

now i have more complicated problem with bisecting :(
on v2.6.34 kernel kde4 compositing effects works fine on my radeon RV370.
on v2.6.35 i'm observing some blinking during effects composition.

with git-bisect i found some bad (in case of screen blinkng) commit:

[http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=59534f
 Merge branch 'drm-for-2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git...]

and earlier branches with good commits:

[http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=ac3ee8
 Merge branch 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwes]

[http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=a7c542
 drm/i915: Fix out of tree builds]

[http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=61dd98
 drm/edid: Fix 1024x768@85Hz]

right after ^61dd98 there is a small change:

[http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=bc35af
 drm/radeon/kms: add query for crtc hw id from crtc id to get info V2]

which causes xserver hangup (100% cpu-hog) on my machine and after this point
i can't really test another git-bisect commit due to xserver hangup.
can i somehow kick-off the ^61dd98 commit from further bisecting to avoid bug masking?

BR,
Pawel.