Srikar Dronamraju <[email protected]> writes: > Lookup the coregroup id from the associativity array.
It's slightly strange that this is called in patch 9, but only properly implemented here in patch 10. I'm not saying you have to squash them together, but it would be good if the change log for patch 9 mentioned that a subsequent commit will complete the implementation and how that affects the behaviour. cheers > If unable to detect the coregroup id, fallback on the core id. > This way, ensure sched_domain degenerates and an extra sched domain is > not created. > > Ideally this function should have been implemented in > arch/powerpc/kernel/smp.c. However if its implemented in mm/numa.c, we > don't need to find the primary domain again. > > If the device-tree mentions more than one coregroup, then kernel > implements only the last or the smallest coregroup, which currently > corresponds to the penultimate domain in the device-tree. > > Cc: linuxppc-dev <[email protected]> > Cc: LKML <[email protected]> > Cc: Michael Ellerman <[email protected]> > Cc: Nicholas Piggin <[email protected]> > Cc: Anton Blanchard <[email protected]> > Cc: Oliver O'Halloran <[email protected]> > Cc: Nathan Lynch <[email protected]> > Cc: Michael Neuling <[email protected]> > Cc: Gautham R Shenoy <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Valentin Schneider <[email protected]> > Cc: Jordan Niethe <[email protected]> > Reviewed-by : Gautham R. Shenoy <[email protected]> > Signed-off-by: Srikar Dronamraju <[email protected]> > --- > Changelog v1 -> v2: > Move coregroup_enabled before getting associativity (Gautham) > > arch/powerpc/mm/numa.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c > index 0d57779e7942..8b3b3ec7fcc4 100644 > --- a/arch/powerpc/mm/numa.c > +++ b/arch/powerpc/mm/numa.c > @@ -1218,6 +1218,26 @@ int find_and_online_cpu_nid(int cpu) > > int cpu_to_coregroup_id(int cpu) > { > + __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0}; > + int index; > + > + if (cpu < 0 || cpu > nr_cpu_ids) > + return -1; > + > + if (!coregroup_enabled) > + goto out; > + > + if (!firmware_has_feature(FW_FEATURE_VPHN)) > + goto out; > + > + if (vphn_get_associativity(cpu, associativity)) > + goto out; > + > + index = of_read_number(associativity, 1); > + if (index > min_common_depth + 1) > + return of_read_number(&associativity[index - 1], 1); > + > +out: > return cpu_to_core_id(cpu); > } > > -- > 2.17.1
