Re: sata_sil24 broken since 2.6.23-rc4-mm1

Matt Mackall
2007-10-03T17:51:39Z

On Wed, Oct 03, 2007 at 07:36:55PM +0200, Torsten Kaiser wrote:
> On 10/3/07, Matt Mackall <mpm@selenic.com> wrote:
> > On Wed, Oct 03, 2007 at 05:55:10PM +0200, Torsten Kaiser wrote:
> > > This patch removes clear_refs_smap() from fs/proc/task_mmu.c by moving
> > > its code to a new function. But during the move the main for-loop from
> > > clear_refs_smap was changed:
> > >
> > > old:
> > > for (vma = mm->mmap; vma; vma = vma->vm_next)
> > > if (vma->vm_mm && !is_vm_hugetlb_page(vma))
> > > walk_page_range(vma->vm_mm, vma->vm_start, vma->vm_end,
> > > &clear_refs_walk, vma);
> > >
> > > new:
> > > for (vma = mm->mmap; vma; vma = vma->vm_next)
> > > if (!is_vm_hugetlb_page(vma))
> > > walk_page_range(mm, vma->vm_start, vma->vm_end,
> > > &clear_refs_walk, vma);
> > >
> > > The walk_page_range() is no longer called on vma->vm_mm, but on mm directly.
> > > I don't know how this can kill the sata_sil24-driver, but at least it
> > > looks suspicious.
> >
> > That code should be fine. Further, it's pretty unlikely that this code
> > ever gets invoked. This whole interface was only recently added by
> > Google folks and its usage is pretty obscure.
> >
> > Oh wait - you're _at_ Google, aren't you? Perhaps you're actually
> > using clear_refs.
>
> No. I'm just using Google Mail.

Ahh, I see. Wasn't aware of the trademark dispute..

> Of note might be, that at the time of this error init has not been
> started. I'm using a program from initramfs to start the RAID.
> The initramfs was primarily build using the genkernel package from
> gentoo, but I have removed some parts of it (kernel modules and some
> other part I no longer remember)

Then I really don't see how these patches can have anything to do with
your problem. They only affect some currently obscure files in /proc
and it's unlikely to have any impact at init time. It's more likely
that there's some code alignment Heisenbug or you got a false negative
somewhere in your bisection.

--
Mathematics is the supreme nostalgia of our time.