Re: [PATCH v13 0/3] scsi: ufs: Add Host Performance Booster Support

[Greg KH]

On Mon, Dec 07, 2020 at 07:35:03PM +0100, Greg KH wrote:
> On Mon, Dec 07, 2020 at 06:26:03PM +0000, Christoph Hellwig wrote:
> > On Mon, Dec 07, 2020 at 07:23:12PM +0100, Greg KH wrote:
> > > What "real workload" test can be run on this to help show if it is
> > > useful or not?  These vendors seem to think it helps for some reason,
> > > otherwise they wouldn't have added it to their silicon :)
> > > 
> > > Should they run fio?  If so, any hints on a config that would be good to
> > > show any performance increases?
> > 
> > A real actual workload that matters.  Then again that was Martins
> > request to even justify it.  I don't think the broken addressing that
> > breaks a whole in the SCSI addressing has absolutely not business being
> > supported in Linux ever.  The vendors should have thought about the
> > design before committing transistors to something that fundamentally
> > does not make sense.
> 
> So "time to boot an android system with this enabled and disabled" would
> be a valid workload, right?  I'm guessing that's what the vendors here
> actually care about, otherwise there is no real stress-test on a UFS
> system that I know of.

Oh, and "supporting stupid hardware specs" is what we do here all the
time, you know that :)

If someone is foolish enough to build it, we usually have to support the
thing, especially if someone else here is willing to do that.  I don't
see where the addressing is "broken", which patch causes that to happen?

thanks,

greg k-h