Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28

Ingo Molnar
2008-09-17T10:40:44Z

* Mike Galbraith <efault-Mmb7MZpHnFY@public.gmane.org> wrote:

> On Wed, 2008-09-17 at 06:40 +0200, Mike Galbraith wrote:
> > On Tue, 2008-09-16 at 17:07 +0300, Ilpo Järvinen wrote:
>
> > > One additional sanity check could be to rebase security 6f0f0fd4963 on top
> > > of the c142bda458a and then see if bisection among those security commits
> > > on top yields to the the same result... Though I doubt it can change much
> > > because there was not that much relevant non-security things in the merge
> > > in question.
> >
> > I'm not a master of git-foo, so that is not an option. However, a dinky
> > bisection c142bda4..847106f very clearly says...
> >
> > marge:..kernel/linux-2.6.27.git # git bisect bad
> > 6f0f0fd496333777d53daff21a4e3b28c4d03a6d is first bad commit
> > commit 6f0f0fd496333777d53daff21a4e3b28c4d03a6d
> > Author: James Morris <jmorris-gx6/JNMH7DfYtjvyW6yDsg@public.gmane.org>
> > Date: Thu Jul 10 17:02:07 2008 +0900
> >
> > security: remove register_security hook
> >
> > The register security hook is no longer required, as the capability
> > module is always registered. LSMs wishing to stack capability as
> > a secondary module should do so explicitly.
> >
> > Signed-off-by: James Morris <jmorris-gx6/JNMH7DfYtjvyW6yDsg@public.gmane.org>
> > Acked-by: Stephen Smalley <sds-+05T5uksL2qpZYMLLGbcSA@public.gmane.org>
> > Acked-by: Greg Kroah-Hartman <gregkh-l3A5Bk7waGM@public.gmane.org>
> >
> > :040000 040000 0177ef46d305e51e27bfcc4350a40577f8ba8d3d 64b64c10a424df4539653a8ee34f1a2329300931 M include
> > :040000 040000 e318891e514de674fd064f6bfad70d5633b1aff1 0dbb38d5aa7fc3e4b2e09dc65796ce7cd5faeb26 M security
>
> Which is high grade horse-pookey.

perhaps re-test commit 6f0f0fd49 and its parent commit, 93cbace7a0.

It looks like a potentially bogus bisection result, but _maybe_ it has
relevance: changes the size of "struct security_operations", which could
have alignment and layout effects on all sorts of kernel variables,
kmalloc sizes, etc.

Ingo