On Thu, Sep 7, 2017 at 5:21 PM, Benjamin Herrenschmidt <b...@kernel.crashing.org> wrote: > On Thu, 2017-09-07 at 15:17 +1000, Anton Blanchard wrote: >> Hi, >> >> > There is a similar issue being worked on w.r.t pseries. >> > >> > https://lkml.kernel.org/r/1502357028-27465-1-git-send-email-bhar...@linux.vnet.ibm.com >> > >> > The question is should we map these regions ? ie, we need to tell the >> > kernel memory region that we would like to hot unplug later so that >> > we avoid doing kernel allocations from that. If we do that, then we >> > can possibly map them via 2M size ? >> >> But all of memory on PowerNV should be able to be hot unplugged, so
For this ideally we need movable mappings for the regions we intend to hot-unplug - no? Otherwise, there is no guarantee that hot-unplug will work >> there are two options as I see it - either increase the memory block >> size, or map everything with 2MB pages. > > Or be smarter and map with 1G when blocks of 1G are available and break > down to 2M where necessary, it shouldn't be too hard. > strict_rwx patches added helpers to do this Balbir Singh.
