| From | Jan H. Schönherr <> | Subject | [RFC 04/60] sched: Replace sd_numa_mask() hack with something sane | Date | Fri, 7 Sep 2018 23:39:51 +0200 |
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Get rid of the global variable sched_domains_curr_level, which is used to pass state into a sd_numa_mask(), which is used as a callback for sched_domain_topology_level->mask().
Extend the ->mask() callback instead, so that it takes the topology level as an extra argument. Provide a backward compatible ->simple_mask() callback, so that existing code can stay as it is.
This enables other users to do queries via ->mask() without having to worry about the global variable. It also opens up the possibility for more generic topologies that require a dynamic number of levels (similar to what NUMA already does on top of the system topology).
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> --- include/linux/sched/topology.h | 11 ++++++++--- kernel/sched/topology.c | 40 ++++++++++++++++++++++------------------ 2 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 530ad856372e..f78534f1cc1e 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -165,7 +165,11 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms); bool cpus_share_cache(int this_cpu, int that_cpu); -typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); +struct sched_domain_topology_level; + +typedef const struct cpumask *(*sched_domain_simple_mask_f)(int cpu); +typedef const struct cpumask *(*sched_domain_mask_f)(struct sched_domain_topology_level *tl, + int cpu); typedef int (*sched_domain_flags_f)(void); #define SDTL_OVERLAP 0x01 @@ -178,10 +182,11 @@ struct sd_data { }; struct sched_domain_topology_level { - sched_domain_mask_f mask; + sched_domain_simple_mask_f simple_mask; sched_domain_flags_f sd_flags; + sched_domain_mask_f mask; int flags; - int numa_level; + int level; struct sd_data data; #ifdef CONFIG_SCHED_DEBUG char *name; diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8b64f3f57d50..0f2c3aa0a097 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1043,7 +1043,6 @@ static void claim_allocations(int cpu, struct sched_domain *sd) enum numa_topology_type sched_numa_topology_type; static int sched_domains_numa_levels; -static int sched_domains_curr_level; int sched_max_numa_distance; static int *sched_domains_numa_distance; @@ -1084,15 +1083,9 @@ sd_init(struct sched_domain_topology_level *tl, struct sd_data *sdd = &tl->data; struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); int sd_id, sd_weight, sd_flags = 0; + const struct cpumask *mask = tl->mask(tl, cpu); -#ifdef CONFIG_NUMA - /* - * Ugly hack to pass state to sd_numa_mask()... - */ - sched_domains_curr_level = tl->numa_level; -#endif - - sd_weight = cpumask_weight(tl->mask(cpu)); + sd_weight = cpumask_weight(mask); if (tl->sd_flags) sd_flags = (*tl->sd_flags)(); @@ -1138,7 +1131,7 @@ sd_init(struct sched_domain_topology_level *tl, #endif }; - cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); + cpumask_and(sched_domain_span(sd), cpu_map, mask); sd_id = cpumask_first(sched_domain_span(sd)); /* @@ -1170,7 +1163,7 @@ sd_init(struct sched_domain_topology_level *tl, sd->idle_idx = 2; sd->flags |= SD_SERIALIZE; - if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { + if (sched_domains_numa_distance[tl->level] > RECLAIM_DISTANCE) { sd->flags &= ~(SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE); @@ -1195,17 +1188,23 @@ sd_init(struct sched_domain_topology_level *tl, return sd; } +static const struct cpumask * +sd_simple_mask(struct sched_domain_topology_level *tl, int cpu) +{ + return tl->simple_mask(cpu); +} + /* * Topology list, bottom-up. */ static struct sched_domain_topology_level default_topology[] = { #ifdef CONFIG_SCHED_SMT - { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, + { cpu_smt_mask, cpu_smt_flags, sd_simple_mask, SD_INIT_NAME(SMT) }, #endif #ifdef CONFIG_SCHED_MC - { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, + { cpu_coregroup_mask, cpu_core_flags, sd_simple_mask, SD_INIT_NAME(MC) }, #endif - { cpu_cpu_mask, SD_INIT_NAME(DIE) }, + { cpu_cpu_mask, NULL, sd_simple_mask, SD_INIT_NAME(DIE) }, { NULL, }, }; @@ -1221,13 +1220,18 @@ void set_sched_topology(struct sched_domain_topology_level *tl) return; sched_domain_topology = tl; + for (; tl->mask || tl->simple_mask; tl++) { + if (tl->simple_mask) + tl->mask = sd_simple_mask; + } } #ifdef CONFIG_NUMA -static const struct cpumask *sd_numa_mask(int cpu) +static const struct cpumask * +sd_numa_mask(struct sched_domain_topology_level *tl, int cpu) { - return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; + return sched_domains_numa_masks[tl->level][cpu_to_node(cpu)]; } static void sched_numa_warn(const char *str) @@ -1446,7 +1450,7 @@ void sched_init_numa(void) */ tl[i++] = (struct sched_domain_topology_level){ .mask = sd_numa_mask, - .numa_level = 0, + .level = 0, SD_INIT_NAME(NODE) }; @@ -1458,7 +1462,7 @@ void sched_init_numa(void) .mask = sd_numa_mask, .sd_flags = cpu_numa_flags, .flags = SDTL_OVERLAP, - .numa_level = j, + .level = j, SD_INIT_NAME(NUMA) }; } -- 2.9.3.1.gcba166c.dirty
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