1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * sched-domains (multiprocessor balancing) flag declarations. |
4 | */ |
5 | |
6 | #ifndef SD_FLAG |
7 | # error "Incorrect import of SD flags definitions" |
8 | #endif |
9 | |
10 | /* |
11 | * Hierarchical metaflags |
12 | * |
13 | * SHARED_CHILD: These flags are meant to be set from the base domain upwards. |
14 | * If a domain has this flag set, all of its children should have it set. This |
15 | * is usually because the flag describes some shared resource (all CPUs in that |
16 | * domain share the same resource), or because they are tied to a scheduling |
17 | * behaviour that we want to disable at some point in the hierarchy for |
18 | * scalability reasons. |
19 | * |
20 | * In those cases it doesn't make sense to have the flag set for a domain but |
21 | * not have it in (some of) its children: sched domains ALWAYS span their child |
22 | * domains, so operations done with parent domains will cover CPUs in the lower |
23 | * child domains. |
24 | * |
25 | * |
26 | * SHARED_PARENT: These flags are meant to be set from the highest domain |
27 | * downwards. If a domain has this flag set, all of its parents should have it |
28 | * set. This is usually for topology properties that start to appear above a |
29 | * certain level (e.g. domain starts spanning CPUs outside of the base CPU's |
30 | * socket). |
31 | */ |
32 | #define SDF_SHARED_CHILD 0x1 |
33 | #define SDF_SHARED_PARENT 0x2 |
34 | |
35 | /* |
36 | * Behavioural metaflags |
37 | * |
38 | * NEEDS_GROUPS: These flags are only relevant if the domain they are set on has |
39 | * more than one group. This is usually for balancing flags (load balancing |
40 | * involves equalizing a metric between groups), or for flags describing some |
41 | * shared resource (which would be shared between groups). |
42 | */ |
43 | #define SDF_NEEDS_GROUPS 0x4 |
44 | |
45 | /* |
46 | * Balance when about to become idle |
47 | * |
48 | * SHARED_CHILD: Set from the base domain up to cpuset.sched_relax_domain_level. |
49 | * NEEDS_GROUPS: Load balancing flag. |
50 | */ |
51 | SD_FLAG(SD_BALANCE_NEWIDLE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
52 | |
53 | /* |
54 | * Balance on exec |
55 | * |
56 | * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. |
57 | * NEEDS_GROUPS: Load balancing flag. |
58 | */ |
59 | SD_FLAG(SD_BALANCE_EXEC, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
60 | |
61 | /* |
62 | * Balance on fork, clone |
63 | * |
64 | * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. |
65 | * NEEDS_GROUPS: Load balancing flag. |
66 | */ |
67 | SD_FLAG(SD_BALANCE_FORK, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
68 | |
69 | /* |
70 | * Balance on wakeup |
71 | * |
72 | * SHARED_CHILD: Set from the base domain up to cpuset.sched_relax_domain_level. |
73 | * NEEDS_GROUPS: Load balancing flag. |
74 | */ |
75 | SD_FLAG(SD_BALANCE_WAKE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
76 | |
77 | /* |
78 | * Consider waking task on waking CPU. |
79 | * |
80 | * SHARED_CHILD: Set from the base domain up to the NUMA reclaim level. |
81 | */ |
82 | SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) |
83 | |
84 | /* |
85 | * Domain members have different CPU capacities |
86 | * |
87 | * SHARED_PARENT: Set from the topmost domain down to the first domain where |
88 | * asymmetry is detected. |
89 | * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. |
90 | */ |
91 | SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) |
92 | |
93 | /* |
94 | * Domain members have different CPU capacities spanning all unique CPU |
95 | * capacity values. |
96 | * |
97 | * SHARED_PARENT: Set from the topmost domain down to the first domain where |
98 | * all available CPU capacities are visible |
99 | * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. |
100 | */ |
101 | SD_FLAG(SD_ASYM_CPUCAPACITY_FULL, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) |
102 | |
103 | /* |
104 | * Domain members share CPU capacity (i.e. SMT) |
105 | * |
106 | * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share |
107 | * CPU capacity. |
108 | * NEEDS_GROUPS: Capacity is shared between groups. |
109 | */ |
110 | SD_FLAG(SD_SHARE_CPUCAPACITY, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
111 | |
112 | /* |
113 | * Domain members share CPU cluster (LLC tags or L2 cache) |
114 | * |
115 | * NEEDS_GROUPS: Clusters are shared between groups. |
116 | */ |
117 | SD_FLAG(SD_CLUSTER, SDF_NEEDS_GROUPS) |
118 | |
119 | /* |
120 | * Domain members share CPU package resources (i.e. caches) |
121 | * |
122 | * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share |
123 | * the same cache(s). |
124 | * NEEDS_GROUPS: Caches are shared between groups. |
125 | */ |
126 | SD_FLAG(SD_SHARE_PKG_RESOURCES, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) |
127 | |
128 | /* |
129 | * Only a single load balancing instance |
130 | * |
131 | * SHARED_PARENT: Set for all NUMA levels above NODE. Could be set from a |
132 | * different level upwards, but it doesn't change that if a |
133 | * domain has this flag set, then all of its parents need to have |
134 | * it too (otherwise the serialization doesn't make sense). |
135 | * NEEDS_GROUPS: No point in preserving domain if it has a single group. |
136 | */ |
137 | SD_FLAG(SD_SERIALIZE, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) |
138 | |
139 | /* |
140 | * Place busy tasks earlier in the domain |
141 | * |
142 | * NEEDS_GROUPS: Load balancing flag. |
143 | */ |
144 | SD_FLAG(SD_ASYM_PACKING, SDF_NEEDS_GROUPS) |
145 | |
146 | /* |
147 | * Prefer to place tasks in a sibling domain |
148 | * |
149 | * Set up until domains start spanning NUMA nodes. Close to being a SHARED_CHILD |
150 | * flag, but cleared below domains with SD_ASYM_CPUCAPACITY. |
151 | * |
152 | * NEEDS_GROUPS: Load balancing flag. |
153 | */ |
154 | SD_FLAG(SD_PREFER_SIBLING, SDF_NEEDS_GROUPS) |
155 | |
156 | /* |
157 | * sched_groups of this level overlap |
158 | * |
159 | * SHARED_PARENT: Set for all NUMA levels above NODE. |
160 | * NEEDS_GROUPS: Overlaps can only exist with more than one group. |
161 | */ |
162 | SD_FLAG(SD_OVERLAP, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) |
163 | |
164 | /* |
165 | * Cross-node balancing |
166 | * |
167 | * SHARED_PARENT: Set for all NUMA levels above NODE. |
168 | * NEEDS_GROUPS: No point in preserving domain if it has a single group. |
169 | */ |
170 | SD_FLAG(SD_NUMA, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) |
171 | |