Re: Another approach of UFSHPB

[Bart Van Assche]

On 2020-05-20 10:55, Christoph Hellwig wrote:
> HPB is a completely fucked up concept and we shoud not merge it at all.
> Especially not with a crazy bullshit vendor extension layer that makes
> it even easier for vendors to implement even worse things than the
> already horrible spec says.  Just stop this crap and implement sane
> interfaces for the next generation hardware instead of wasting your
> time on this idiotic idea.

Hi Christoph,

What exactly is it that you are not happy about? Is it the concept of
using host memory to store L2P translation information or how that
concept has been translated into SCSI commands (HPB READ BUFFER, HPB
READ and HPB WRITE BUFFER)?

In the former case: aren't Open-Channel SSDs another example of storage
devices for which the L2P translation tables are maintained in host
memory? Didn't the driver for Fusion-io SSDs also maintain the L2P
mapping in host memory?

Do you agree that HPB UFS storage devices are already being used widely
and hence that not accepting this functionality in the upstream kernel
will force users of HPB devices to maintain HPB code outside the kernel
tree? Isn't one of the goals of the Linux kernel project to increase its
user base?

Bart.