Messages in this thread | | | Subject | Re: [PATCH v2 0/1] arm: topology: parse the topology from the dt | From | Dietmar Eggemann <> | Date | Fri, 16 Apr 2021 12:39:30 +0200 |
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On 16/04/2021 11:32, Valentin Schneider wrote: > On 16/04/21 15:47, Ruifeng Zhang wrote: >> For more requirements, if all cores in one physical cluster, the >> {aff2} of all cores are the same value. >> i.e. the sc9863a, >> core0: 0000000081000000 >> core1: 0000000081000100 >> core2: 0000000081000200 >> core3: 0000000081000300 >> core4: 0000000081000400 >> core5: 0000000081000500 >> core6: 0000000081000600 >> core7: 0000000081000700 >> >> According to MPIDR all cores will parse to the one cluster, but it's >> the big.LITTLE system, it's need two logic cluster for schedule or >> cpufreq. >> So I think it's better to add the logic of parse topology from DT. > > Ah, so it's a slightly different issue, but still one that requires a > different means of specifying topology.
I'm confused. Do you have the MT bit set to 1 then? So the issue that the mpidr handling in arm32's store_cpu_topology() is not correct does not exist?
With DynamIQ you have only *one* cluster, you should also be able to run your big.LITTLE system with only an MC sched domain.
# cat /proc/schedstat cpu0 .... domain0 ff ... <- MC ...
You can introduce a cpu-map to create what we called Phantom Domains in Android products.
# cat /proc/schedstat
cpu0 .... domain0 0f ... <- MC domain1 ff ... < DIE
Is this what you need for your arm32 kernel system? Adding the possibility to parse cpu-map to create Phantom Domains?
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