On Tue, May 26, 2020 at 01:52:21PM -0700, Dan Williams wrote:
On Tue, May 26, 2020 at 1:49 PM Jeff Moyer <jmoyer(a)redhat.com>
> 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.
Well, if it was always there, then there is nothing to fix, and I
misremembered that we went backwards.
> > 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.
Thanks for that offer, but outside of a clear regression I don't think
this meets -stable criteria.
I agree, I'll drop this series from my pending-queue.