Messages in this thread | | | Date | Sat, 3 Sep 2022 08:00:55 +0200 | From | Greg KH <> | Subject | Re: [PATCH v2] arch_topology: Make cluster topology span at least SMT CPUs |
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On Thu, Aug 25, 2022 at 05:20:07PM +0800, Yicong Yang wrote: > 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);
As the kernel-test robot reported, this breaks the build on some architectures, so I'll go and revert it from my tree now.
thanks,
greg k-h
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