Re: [PATCH v2] libnvdimm: re-enable deep flush for pmem devices
Dave Jiang <dave.jiang(a)intel.com> writes:
Re-enable deep flush so that users always have a way to be sure that
a write
does make it all the way out to the NVDIMM. The PMEM driver writes always
make it "all the way to the NVDIMM", and it relies on the ADR mechanism to
flush the write buffers on power failure. Deep flush is there to explicitly
flush those write buffers to protect against (rare) ADR failure.
This change prevents a regression in deep flush behavior so that applications
can continue to depend on fsync() as a mechanism to trigger deep flush in the
filesystem-dax case.
That's still very confusing text. Specifically, the part where you say
that pmem driver writes always make it to the DIMM. I think the
changelog could start with "Deep flush is there to explicitly flush
write buffers...." Anyway, the fix looks right to me.
Reviewed-by: Jeff Moyer <jmoyer(a)redhat.com>