Dan Williams <dan.j.williams(a)intel.com> writes:
> What problems with 5.4.y and 5.6.y is this series fixing
> that used to work before?
The "used to work" bug fixed by this set is the fact that the kernel
used to force a 128MB (memory hotplug section size) alignment padding
on all persistent memory namespaces to enable DAX operation. The
support for sub-sections (2MB) dropped forced alignment padding, but
unfortunately introduced a regression for the case of trying to create
multiple unaligned namespaces. When that bug triggers namespace
creation for the region is disabled, iirc, previously that lockout
scenario was prevented.
Jeff, can you corroborate this?
So, I don't pretend to remember the exact state of brokenness for each
iteration. :) As far as I can recall, though, the issue you describe
with a misaligned namespace preventing further namespace creation was
present in all kernels up until it was finally fixed.
I otherwise agree, if the above never worked then this can all wait
for v5.7 upgrades.
I can test specific kernel versions if that would help out.