/* SPDX-License-Identifier: GPL-2.0 */ /* * sched-domains (multiprocessor balancing) flag declarations. */ #ifndef SD_FLAG # error "Incorrect import of SD flags definitions" #endif /* * Hierarchical metaflags * * SHARED_CHILD: These flags are meant to be set from the base domain upwards. * If a domain has this flag set, all of its children should have it set. This * is usually because the flag describes some shared resource (all CPUs in that * domain share the same resource), or because they are tied to a scheduling * behaviour that we want to disable at some point in the hierarchy for * scalability reasons. * * In those cases it doesn't make sense to have the flag set for a domain but * not have it in (some of) its children: sched domains ALWAYS span their child * domains, so operations done with parent domains will cover CPUs in the lower * child domains. * * * SHARED_PARENT: These flags are meant to be set from the highest domain * downwards. If a domain has this flag set, all of its parents should have it * set. This is usually for topology properties that start to appear above a * certain level (e.g. domain starts spanning CPUs outside of the base CPU's * socket). */ #define SDF_SHARED_CHILD 0x1 #define SDF_SHARED_PARENT 0x2 /* * Behavioural metaflags * * NEEDS_GROUPS: These flags are only relevant if the domain they are set on has * more than one group. This is usually for balancing flags (load balancing * involves equalizing a metric between groups), or for flags describing some * shared resource (which would be shared between groups). */ #define SDF_NEEDS_GROUPS 0x4 /* * Balance when about to become idle * * SHARED_CHILD: Set from the base domain up to cpuset.sched_relax_domain_level. * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_BALANCE_NEWIDLE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Balance on exec * * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_BALANCE_EXEC, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Balance on fork, clone * * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_BALANCE_FORK, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Balance on wakeup * * SHARED_CHILD: Set from the base domain up to cpuset.sched_relax_domain_level. * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_BALANCE_WAKE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Consider waking task on waking CPU. * * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. */ SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) /* * Domain members have different CPU capacities * * SHARED_PARENT: Set from the topmost domain down to the first domain where * asymmetry is detected. * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. */ SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* * Domain members have different CPU capacities spanning all unique CPU * capacity values. * * SHARED_PARENT: Set from the topmost domain down to the first domain where * all available CPU capacities are visible * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. */ SD_FLAG(SD_ASYM_CPUCAPACITY_FULL, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* * Domain members share CPU capacity (i.e. SMT) * * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share * CPU capacity. * NEEDS_GROUPS: Capacity is shared between groups. */ SD_FLAG(SD_SHARE_CPUCAPACITY, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Domain members share CPU cluster (LLC tags or L2 cache) * * NEEDS_GROUPS: Clusters are shared between groups. */ SD_FLAG(SD_CLUSTER, SDF_NEEDS_GROUPS) /* * Domain members share CPU Last Level Caches * * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share * the same cache(s). * NEEDS_GROUPS: Caches are shared between groups. */ SD_FLAG(SD_SHARE_LLC, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) /* * Only a single load balancing instance * * SHARED_PARENT: Set for all NUMA levels above NODE. Could be set from a * different level upwards, but it doesn't change that if a * domain has this flag set, then all of its parents need to have * it too (otherwise the serialization doesn't make sense). * NEEDS_GROUPS: No point in preserving domain if it has a single group. */ SD_FLAG(SD_SERIALIZE, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* * Place busy tasks earlier in the domain * * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_ASYM_PACKING, SDF_NEEDS_GROUPS) /* * Prefer to place tasks in a sibling domain * * Set up until domains start spanning NUMA nodes. Close to being a SHARED_CHILD * flag, but cleared below domains with SD_ASYM_CPUCAPACITY. * * NEEDS_GROUPS: Load balancing flag. */ SD_FLAG(SD_PREFER_SIBLING, SDF_NEEDS_GROUPS) /* * sched_groups of this level overlap * * SHARED_PARENT: Set for all NUMA levels above NODE. * NEEDS_GROUPS: Overlaps can only exist with more than one group. */ SD_FLAG(SD_OVERLAP, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* * Cross-node balancing * * SHARED_PARENT: Set for all NUMA levels above NODE. * NEEDS_GROUPS: No point in preserving domain if it has a single group. */ SD_FLAG(SD_NUMA, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS)
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