Ampere Altra defines CPU clusters in the ACPI PPTT. They share a Snoop
Control Unit, but have no shared CPU-side last level cache.
cpu_coregroup_mask() will return a cpumask with weight 1, while
cpu_clustergroup_mask() will return a cpumask with weight 2.
As a result, build_sched_domain() will BUG() once per CPU with:
BUG: arch topology borken
the CLS domain not a subset of the MC domain
The MC level cpumask is then extended to that of the CLS child, and is
later removed entirely as redundant. This sched domain topology is an
improvement over previous topologies, or those built without
SCHED_CLUSTER, particularly for certain latency sensitive workloads.
With the current scheduler model and heuristics, this is a desirable
default topology for Ampere Altra and Altra Max system.
Rather than create a custom sched domains topology structure and
introduce new logic in arch/arm64 to detect these systems, update the
core_mask so coregroup is never a subset of clustergroup, extending it
to cluster_siblings if necessary. Only do this if CONFIG_SCHED_CLUSTER
is enabled to avoid also changing the topology (MC) when
CONFIG_SCHED_CLUSTER is disabled.
This has the added benefit over a custom topology of working for both
symmetric and asymmetric topologies. It does not address systems where
the CLUSTER topology is above a populated MC topology, but these are not
considered today and can be addressed separately if and when they
appear.
The final sched domain topology for a 2 socket Ampere Altra system is
unchanged with or without CONFIG_SCHED_CLUSTER, and the BUG is avoided:
For CPU0:
CONFIG_SCHED_CLUSTER=y
CLS [0-1]
DIE [0-79]
NUMA [0-159]
CONFIG_SCHED_CLUSTER is not set
DIE [0-79]
NUMA [0-159]
Signed-off-by: Darren Hart <darren(a)os.amperecomputing.com>
Suggested-by: Barry Song <song.bao.hua(a)hisilicon.com>
Reviewed-by: Barry Song <song.bao.hua(a)hisilicon.com>
Acked-by: Sudeep Holla <sudeep.holla(a)arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann(a)arm.com>
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael(a)kernel.org>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Will Deacon <will(a)kernel.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Vincent Guittot <vincent.guittot(a)linaro.org>
Cc: D. Scott Phillips <scott(a)os.amperecomputing.com>
Cc: Ilkka Koskinen <ilkka(a)os.amperecomputing.com>
Cc: <stable(a)vger.kernel.org> # 5.16.x
---
v1: Drop MC level if coregroup weight == 1
v2: New sd topo in arch/arm64/kernel/smp.c
v3: No new topo, extend core_mask to cluster_siblings
v4: Rebase on 5.18-rc1 for GregKH to pull. Add IS_ENABLED(CONFIG_SCHED_CLUSTER).
v5: Rebase on 5.18-rc2 for GregKH to pull. Add collected tags. No other changes.
drivers/base/arch_topology.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 1d6636ebaac5..5497c5ab7318 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -667,6 +667,15 @@ const struct cpumask *cpu_coregroup_mask(int cpu)
core_mask = &cpu_topology[cpu].llc_sibling;
}
+ /*
+ * For systems with no shared cpu-side LLC but with clusters defined,
+ * extend core_mask to cluster_siblings. The sched domain builder will
+ * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
+ */
+ if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
+ cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
+ core_mask = &cpu_topology[cpu].cluster_sibling;
+
return core_mask;
}
--
2.34.1
My Greetings,
My name's Hon. Barrister Matthias, I am sending this brief letter to
solicit your support. I had a client who is an Indian and his name is
Mr. Gurbhagat Singh Bhatti , he was a dealer in magnesite minerals
here in Austria and also a Gas dealer in Russia. He died six years
ago in Russia after a Gas explosion in one of his dealing offices
which led to the death of both him and his wife.
He deposited the sum of 4.5 million euro in one of the legendary banks
here in Austria. I have tried all I could to get in touch with any of
his friends or family members but, no way because he had no child. And
the recent death of Covid 19 killed his only brothers in India last
year.
So I want you to apply to the bank as his Business partner so that the
bank can release Mr. Gurbhagat Singh Bhatti funds into your bank
account. I will provide you the guidelines on how to contact the bank
and we have to do this with trust, because I don't want the bank to
transfer the fund into Government treasury account as an unclaimed
fund, so i need your response
Warm Regards,
Hon. Barrister Matthias
We were failing to call kasan_malloc() from __kmalloc_*track_caller()
which was causing us to sometimes fail to produce KASAN error reports
for allocations made using e.g. devm_kcalloc(), as the KASAN poison was
not being initialized. Fix it.
Signed-off-by: Peter Collingbourne <pcc(a)google.com>
Cc: <stable(a)vger.kernel.org> # 5.15
---
The same problem is being fixed upstream in:
https://lore.kernel.org/all/20220817101826.236819-6-42.hyeyoo@gmail.com/
as part of a larger patch series, but this more targeted fix seems
more suitable for the stable kernel. Hyeonggon, maybe you can add
this patch to the start of your series and it can be picked up
by the stable maintainers.
mm/slub.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/slub.c b/mm/slub.c
index 862dbd9af4f5..875c569c5cbe 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4926,6 +4926,8 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
/* Honor the call site pointer we received. */
trace_kmalloc(caller, ret, s, size, s->size, gfpflags);
+ ret = kasan_kmalloc(s, ret, size, gfpflags);
+
return ret;
}
EXPORT_SYMBOL(__kmalloc_track_caller);
@@ -4957,6 +4959,8 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
/* Honor the call site pointer we received. */
trace_kmalloc_node(caller, ret, s, size, s->size, gfpflags, node);
+ ret = kasan_kmalloc(s, ret, size, gfpflags);
+
return ret;
}
EXPORT_SYMBOL(__kmalloc_node_track_caller);
--
2.37.2.789.g6183377224-goog