ia64: ensure proper NUMA distance and possible map initialization

commit b22a8f7b4bde4e4ab73b64908ffd5d90ecdcdbfd upstream.

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@physik.fu-berlin.de
Link: https://lkml.kernel.org/r/20210318130617.896309-1-valentin.schneider@arm.com
Fixes: 620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort")
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: Sergei Trofimovich <slyfox@gentoo.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ dannf: Use node_distance instead of slit_distance since this is before
  the rename that occurred in commit ef78e5ec9214 ("ia64: export
  node_distance function"), plus a minor context adjustment ]
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 1dacbf5e9e09a5a71f9e21bd5fd88eed8199e823..0c1dac64e77b8d71dbaa7618974f26cb041efa5e 100644 (file)
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -537,7 +537,8 @@ 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;
+               node_distance(0, 0) = LOCAL_DISTANCE;
+               goto out;
        }
 
        /*
@@ -580,7 +581,7 @@ void __init acpi_numa_fixup(void)
                        for (j = 0; j < MAX_NUMNODES; j++)
                                node_distance(i, j) = i == j ? LOCAL_DISTANCE :
                                                        REMOTE_DISTANCE;
-               return;
+               goto out;
        }
 
        memset(numa_slit, -1, sizeof(numa_slit));
@@ -605,6 +606,8 @@ void __init acpi_numa_fixup(void)
                printk("\n");
        }
 #endif
+out:
+       node_possible_map = node_online_map;
 }
 #endif                         /* CONFIG_ACPI_NUMA */