On 3/11/2022 1:51 PM, Keith Busch wrote:
On Fri, Mar 11, 2022 at 12:19:38PM -0800, Luis Chamberlain wrote:
NAND has no PO2 requirement. The emulation effort was only done to help
add support for !PO2 devices because there is no alternative. If we
however are ready instead to go down the avenue of removing those
restrictions well let's go there then instead. If that's not even
something we are willing to consider I'd really like folks who stand
behind the PO2 requirement to stick their necks out and clearly say that
their hw/fw teams are happy to deal with this requirement forever on ZNS.
Regardless of the merits of the current OS requirement, it's a trivial
matter for firmware to round up their reported zone size to the next
power of 2. This does not create a significant burden on their part, as
far as I know.
Sure wonder why !PO2 keeps coming up if it's so trivial to fix in firmware as you claim.
I actually find the hubris of the Linux community wrt the whole PO2 requirement
pretty exhausting.
Consider that some SSD manufacturers are having to rely on a NAND shortage and
existing ASIC architecture limitations that may define the sizes of their erase blocks
and write units. A !PO2 implementation in the Linux kernel would enable consumers
to be able to choose more options in the marketplace for their Linux ZNS application.
