Re: Large amount of scsi-sgpool objects

Thomas Gleixner
2009-03-04T20:11:01Z

On Wed, 4 Mar 2009, Andrew Morton wrote:
> On Wed, 4 Mar 2009 12:24:55 +0100
> Ingo Molnar <mingo@elte.hu> wrote:
>
> > FYI, we still have not tracked down the SCSI bug. Latest
> > tip:master is able to boot and work on the affected systems,
> > while the upstream kernel does not even boot because the fix (or
> > the revert, should the fix be deemed unwanted) is stuck in the
> > SCSI tree.
>
> <wakes up>
>
> There are fixes in the scsi tree?
>
> Does the scsi tree fix all the regressions which you guys are seeing?
>
> I must say that it seems to be awfully late in the cycle to have this
> amount of breakage remaining in mainline when we know exactly which
> patches need to be reverted to unbreak things.

We are looking at two breakages:

1) the hang which is observed on AIC7xxx, which is identified (Ingo
tracked it down to a bunch of commits). There is a tentative fix right
now, which needs more testing and the ack of James. James has some
objections which stalled the fix, but I did not come around to dig
into this yet as I'm busy with #2.

2) a crash caused by blk_rq_map_sg() using more sg entries than the
code which setup the request estimated. That one is dangerous, it
already trashed a complete filesystem. I'm in the process of providing
the necessary debug data, as I found a way to reproduce the problem
halfsways.

Thanks,

tglx