Messages in this thread |  | | From | Valentin Schneider <> | | Subject | Re: [PATCH 2/2] sched/topology: optimize topology_span_sane() | | Date | Tue, 06 Aug 2024 17:50:23 +0200 |
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On 02/08/24 10:57, Yury Norov wrote: > The function may call cpumask_equal with tl->mask(cpu) == tl->mask(i), > even when cpu != i.
For which architecture have you observed this? AFAIA all implementations of tl->sched_domain_mask_f are built on a per-CPU cpumask.
e.g. for the default topology, we have:
cpu_smt_mask() -> topology_sibling_cpumask()
which is implemented as:
arch/loongarch/include/asm/topology.h:35:#define topology_sibling_cpumask(cpu) (&cpu_sibling_map[cpu]) arch/mips/include/asm/topology.h:18:#define topology_sibling_cpumask(cpu) (&cpu_sibling_map[cpu]) arch/powerpc/include/asm/topology.h:139:#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu)) arch/s390/include/asm/topology.h:31:#define topology_sibling_cpumask(cpu) (&cpu_topology[cpu].thread_mask) arch/sparc/include/asm/topology_64.h:50:#define topology_sibling_cpumask(cpu) (&per_cpu(cpu_sibling_map, cpu)) arch/x86/include/asm/topology.h:186:#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu)) include/linux/arch_topology.h:91:#define topology_sibling_cpumask(cpu) (&cpu_topology[cpu].thread_sibling) include/linux/topology.h:218:#define topology_sibling_cpumask(cpu) cpumask_of(cpu)
and ditto for cpu_coregroup_mask() & cpu_cpu_mask().
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