From: Valentin Schneider <valentin.schneider@xxxxxxx>
Subject: ia64: ensure proper NUMA distance and possible map initialization
John Paul reported a warning about bogus NUMA distance values spurred by
commit:
620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort")
In this case, the afflicted machine comes up with a reported 256 possible
nodes, all of which are 0 distance away from one another. This was
previously silently ignored, but is now caught by the aforementioned
commit.
The culprit is ia64's node_possible_map which remains unchanged from its
initialization value of NODE_MASK_ALL. In John's case, the machine
doesn't have any SRAT nor SLIT table, but AIUI the possible map remains
untouched regardless of what ACPI tables end up being parsed. Thus,
!online && possible nodes remain with a bogus distance of 0 (distances \in
[0, 9] are "reserved and have no meaning" as per the ACPI spec).
Follow x86 / drivers/base/arch_numa's example and set the possible map to
the parsed map, which in this case seems to be the online map.
Link: http://lore.kernel.org/r/255d6b5d-194e-eb0e-ecdd-97477a534441@xxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20210318130617.896309-1-valentin.schneider@xxxxxxx
Fixes: 620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort")
Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Reported-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Tested-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Tested-by: Sergei Trofimovich <slyfox@xxxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Anatoly Pugachev <matorola@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/kernel/acpi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/arch/ia64/kernel/acpi.c~ia64-ensure-proper-numa-distance-and-possible-map-initialization
+++ a/arch/ia64/kernel/acpi.c
@@ -446,7 +446,8 @@ void __init acpi_numa_fixup(void)
if (srat_num_cpus == 0) {
node_set_online(0);
node_cpuid[0].phys_id = hard_smp_processor_id();
- return;
+ slit_distance(0, 0) = LOCAL_DISTANCE;
+ goto out;
}
/*
@@ -489,7 +490,7 @@ void __init acpi_numa_fixup(void)
for (j = 0; j < MAX_NUMNODES; j++)
slit_distance(i, j) = i == j ?
LOCAL_DISTANCE : REMOTE_DISTANCE;
- return;
+ goto out;
}
memset(numa_slit, -1, sizeof(numa_slit));
@@ -514,6 +515,8 @@ void __init acpi_numa_fixup(void)
printk("\n");
}
#endif
+out:
+ node_possible_map = node_online_map;
}
#endif /* CONFIG_ACPI_NUMA */
_
