Re: [BUG] 2.6.29-rc6-2450cf in scsi_lib.c (was: Large amount of scsi-sgpool)objects

[FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>]

On Thu, 5 Mar 2009 11:30:24 +0100
Jens Axboe <jens.axboe@oracle.com> wrote:

> > > While merging that, I think we can do better than this. Essentially we
> > > just need to have __blk_recalc_rq_segments() track the back bio as well,
> > > then we don't have to pass in a pointer for segment sizes.
> > > 
> > > Totally untested, comments welcome...
> > 
> > Yeah, I think that updating bi_seg_front_size and bi_seg_back_size at
> > one place, __blk_recalc_rq_segments, is better. I thought about the
> > same way. But we are already in -rc7 and this must go into mainline
> > now. So I chose a less-intrusive way (similar to what we have done in
> > the past).
> > 
> > As you know, the merging code is really complicated and we could
> > overlook stuff easily. ;) It might be better to simplify the merging
> > code a bit.
> 
> If someone (Ingo?) is willing to test the last variant, I'd much rather
> add that. It does simplify it (imho), and it kills 23 lines while only
> adding 9. But a quick response would be nice, then I can ask Linus to
> pull it later today.

I prefer to keep your change for 2.6.30 but if you want to push it
now, it's fine by me.

Ingo, you can quickly hit this bug without the patch?

I've not hit this bug while I've been performing intensive I/Os for
the last three hours. And I thought that Thomas took two hours to hit
this. So maybe it's too early to give 'Tested-by'. With 
max_segment_size decreased, we might hit this easier.