Re: repeatable slab corruption with LTP msgctl08

[Andrew Morton]

On Wed, 11 Jun 2008 23:34:49 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Wed, 11 Jun 2008 22:13:24 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> 
> > Running current mainline on my old 2-way PIII.  Distro is RH FC1.  LTP
> > version is ltp-full-20070228 (lots of retro-computing there).
> > 
> > Config is at http://userweb.kernel.org/~akpm/config-vmm.txt
> > 
> > 
> > ./testcases/bin/msgctl08 crashes after ten minutes or so:
> 
> ah, it runs to completion in about ten seconds on 2.6.25, so it'll be
> easy for someone to bisect it.
> 
> What's that?  Sigh.  OK.  I wasn't doing anything much anyway.

Oh drat.  git-bisect tells me that this one-year-old msgctl08's
execution time vastly increased when we added

commit f7bf3df8be72d98afa84f5ff183e14c1ba1e560d
Author: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Date:   Tue Apr 29 01:00:39 2008 -0700

    ipc: scale msgmni to the amount of lowmem
    

But we already knew that, and LTP got changed to fix it.

So I was wrong in assuming that the long-execution-time correlates with
the slab-corruption bug.

And the slab corruption bug takes half an hour to reproduce and an
unknown amount of time to not-reproduce.  I don't think I'll be able to
complete this before I disappear for over a week.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/