Re: aic94xx: failing on high load (another data point)

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Wed, 2008-02-20 at 17:54 +0800, Keith Hopkins wrote:
> On 02/20/2008 11:48 AM, James Bottomley wrote:
> > On Tue, 2008-02-19 at 10:22 -0600, James Bottomley wrote:
> >> I'll see if I can come up with patches to fix this ... or at least
> >> mitigate the problems it causes.
> > 
> > Darrick's working on the ascb sequencer use after free problem.
> > 
> > I looked into some of the error handling in libsas, and apparently
> > that's a bit of a huge screw up too.  There are a number of places where
> > we won't complete a task that is being errored out and thus causes
> > timeout errors.  This patch is actually for libsas to fix all of this.
> > 
> > I've managed to reproduce some of your problem by firing random resets
> > across a disk under load, and this recovers the protocol errors for me.
> > However, I can't reproduce the TMF timeout which caused the sequencer
> > screw up, so you still need to wait for Darrick's fix as well.
> > 
> > James
> > 
> 
> Hi James, Darrick,
> 
>   Thanks again for looking more into this.  I'll wait for Darrick's
> patch and try it together with this libsas patch.  Should I leave
> James' first patch in also?

Yes, that's a requirement just to get the REQ_TASK_ABORT for the
protocol errors actually to work ...

I'm afraid this is like peeling an onion as I said .. and you're going
to build up layers of patches.  However, the ones that are obvious bug
fixes and I can test (all of them so far), I'm putting in the rc fixes
tree of SCSI, so you can download a rollup here:

http://www.kernel.org/pub/linux/kernel/people/jejb/scsi-rc-fixes-2.6.diff

James