Re: [Lsf-pc] [LSF/MM ATTEND] Interested in attending LSF

Re: [Lsf-pc] [LSF/MM ATTEND] Interested in attending LSF

[Jan Kara]

On Mon 09-01-17 12:04:31, Nauman Rafique via Lsf-pc wrote:
> I manage one of the storage teams at Google working on SSDs, iSCSI, SMR
> etc. I have worked on cgroup support on block layer in the past, and whole
> lot on different layers of SSD stack (drivers, userland daemons, etc).
> 
> The topis that I am interested in include
> - use of SSDs as slow memory devices. Do we have the right kind of
> interfaces for those exposed by the kernel.

So AFAIK SSDs are not directly addressable by the CPU so you can use them
as a swap but I fail to see how you'd like to use them as "slow memory"...

> - high efficiency, fine grained snapshots in kernel filesystems. Should it
> be a facility in VFS.

Are you speaking about the userspace API for snapshots (in that direction
we already have clone_file_range()) or the actual implementation? Because
the implementation requires support in each individual filesystem so I'm
not sure what VFS could do about it...

> - Can we apply DAX to SSDs, why shouldn't we?

We cannot until SSDs are directly addressable by the CPU - and then they
are essentially just a persistent memory.

									Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR