On Tue, Nov 22, 2016 at 11:01:32AM -0800, Dan Williams wrote: > On Tue, Nov 22, 2016 at 10:54 AM, Kees Cook <keesc...@chromium.org> wrote: > > On Tue, Nov 22, 2016 at 9:26 AM, Dan Williams <dan.j.willi...@intel.com> > > wrote: > >> No, you're right, we need to handle multiple ranges. Since the > >> mem_avoid array is statically allocated perhaps we can handle up to 4 > >> memmap= entries, but past that point disable kaslr for that boot? > > > > Yeah, that seems fine to me. I assume it's rare to have 4? > > > > It should be rare to have *one* since ACPI 6.0 added support for > communicating persistent memory ranges. However there are legacy > nvdimm users that I know are doing at least 2, but I have hard time > imagining they would ever do more than 4.
I doubt it's rare amongst the people using RAM to emulate pmem for filesystem testing purposes. My "pmem" test VM always has at least 2 ranges set to give me two discrete pmem devices, and I have used 4 from time to time to do things like test multi-volume scratch XFS filesystems in xfstests (i.e. data, log and realtime volumes) so I didn't need to play games with partitioning or DM... Cheers, Dave. -- Dave Chinner da...@fromorbit.com
