Changing cpu <-> node relationships at runtime, as the pseries
platform code attempts to do for LPM, PRRN, and VPHN is essentially
unsupported by core subsystems. [1]
While more significant changes (i.e. discarding all that code) likely
are in store, these patches are a minimally invasive way to disable
the problem behavior in a way that should be suitable for backporting
to -stable and distros, and is an improvement on the current
situation.
Note: this doesn't affect use of VPHN at boot time for detecting
shared processor node assignments. Only runtime VPHN-initiated
reassignments are disabled.
[1] E.g. see the discussion here:
https://lore.kernel.org/lkml/20180831115350.gc8...@linux.vnet.ibm.com/T/#u
Nathan Lynch (2):
powerpc/numa: improve control of topology updates
powerpc/numa: document topology_updates_enabled, disable by default
arch/powerpc/mm/numa.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
--
2.20.1
