linux_dsm_epyc7002/arch/arm64/include/asm/topology.h
Jeremy Linton 37c3ec2d81 arm64: topology: divorce MC scheduling domain from core_siblings
Now that we have an accurate view of the physical topology
we need to represent it correctly to the scheduler. Generally MC
should equal the LLC in the system, but there are a number of
special cases that need to be dealt with.

In the case of NUMA in socket, we need to assure that the sched
domain we build for the MC layer isn't larger than the DIE above it.
Similarly for LLC's that might exist in cross socket interconnect or
directory hardware we need to assure that MC is shrunk to the socket
or NUMA node.

This patch builds a sibling mask for the LLC, and then picks the
smallest of LLC, socket siblings, or NUMA node siblings, which
gives us the behavior described above. This is ever so slightly
different than the similar alternative where we look for a cache
layer less than or equal to the socket/NUMA siblings.

The logic to pick the MC layer affects all arm64 machines, but
only changes the behavior for DT/MPIDR systems if the NUMA domain
is smaller than the core siblings (generally set to the cluster).
Potentially this fixes a possible bug in DT systems, but really
it only affects ACPI systems where the core siblings is correctly
set to the socket siblings. Thus all currently available ACPI
systems should have MC equal to LLC, including the NUMA in socket
machines where the LLC is partitioned between the NUMA nodes.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 17:28:09 +01:00

49 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_TOPOLOGY_H
#define __ASM_TOPOLOGY_H
#include <linux/cpumask.h>
struct cpu_topology {
int thread_id;
int core_id;
int package_id;
int llc_id;
cpumask_t thread_sibling;
cpumask_t core_sibling;
cpumask_t llc_siblings;
};
extern struct cpu_topology cpu_topology[NR_CPUS];
#define topology_physical_package_id(cpu) (cpu_topology[cpu].package_id)
#define topology_core_id(cpu) (cpu_topology[cpu].core_id)
#define topology_core_cpumask(cpu) (&cpu_topology[cpu].core_sibling)
#define topology_sibling_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
void init_cpu_topology(void);
void store_cpu_topology(unsigned int cpuid);
const struct cpumask *cpu_coregroup_mask(int cpu);
#ifdef CONFIG_NUMA
struct pci_bus;
int pcibus_to_node(struct pci_bus *bus);
#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \
cpu_all_mask : \
cpumask_of_node(pcibus_to_node(bus)))
#endif /* CONFIG_NUMA */
#include <linux/arch_topology.h>
/* Replace task scheduler's default frequency-invariant accounting */
#define arch_scale_freq_capacity topology_get_freq_scale
/* Replace task scheduler's default cpu-invariant accounting */
#define arch_scale_cpu_capacity topology_get_cpu_scale
#include <asm-generic/topology.h>
#endif /* _ASM_ARM_TOPOLOGY_H */