Messages in this thread Patch in this message | | | From | Yicong Yang <> | Subject | [PATCH v2] arch_topology: Make cluster topology span at least SMT CPUs | Date | Thu, 25 Aug 2022 17:20:07 +0800 |
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From: Yicong Yang <yangyicong@hisilicon.com>
Currently cpu_clustergroup_mask() will return CPU mask if cluster span more or the same CPUs as cpu_coregroup_mask(). This will result topology borken on non-Cluster SMT machines when building with CONFIG_SCHED_CLUSTER=y.
Test with: qemu-system-aarch64 -enable-kvm -machine virt \ -net none \ -cpu host \ -bios ./QEMU_EFI.fd \ -m 2G \ -smp 48,sockets=2,cores=12,threads=2 \ -kernel $Image \ -initrd $Rootfs \ -nographic \ -append "rdinit=init console=ttyAMA0 sched_verbose loglevel=8"
We'll get below error: [ 3.084568] BUG: arch topology borken [ 3.084570] the SMT domain not a subset of the CLS domain
Since cluster is a level higher than SMT, fix this by making cluster spans at least SMT CPUs.
Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Ionela Voinescu <ionela.voinescu@arm.com> Fixes: bfcc4397435d ("arch_topology: Limit span of cpu_clustergroup_mask()") Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> --- Change since v1: - mention the kernel config CONFIG_SCHED_CLUSTER=y, per Ionela Link:https://lore.kernel.org/lkml/20220823073044.58697-1-yangyicong@huawei.com/
drivers/base/arch_topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 0424b59b695e..0056a1273275 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -724,7 +724,7 @@ const struct cpumask *cpu_clustergroup_mask(int cpu) */ if (cpumask_subset(cpu_coregroup_mask(cpu), &cpu_topology[cpu].cluster_sibling)) - return get_cpu_mask(cpu); + return cpu_smt_mask(cpu); return &cpu_topology[cpu].cluster_sibling; } -- 2.24.0
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