diff options
Diffstat (limited to 'kernel/sched/ext_idle.c')
| -rw-r--r-- | kernel/sched/ext_idle.c | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 66da03cc0b33..6d29d3cbc670 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -138,6 +138,7 @@ found: goto retry; } +#ifdef CONFIG_NUMA /* * Tracks nodes that have not yet been visited when searching for an idle * CPU across all available nodes. @@ -186,6 +187,13 @@ static s32 pick_idle_cpu_from_online_nodes(const struct cpumask *cpus_allowed, i return cpu; } +#else +static inline s32 +pick_idle_cpu_from_online_nodes(const struct cpumask *cpus_allowed, int node, u64 flags) +{ + return -EBUSY; +} +#endif /* * Find an idle CPU in the system, starting from @node. @@ -447,11 +455,18 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, const struct cpumask *llc_cpus = NULL, *numa_cpus = NULL; const struct cpumask *allowed = cpus_allowed ?: p->cpus_ptr; int node = scx_cpu_node_if_enabled(prev_cpu); + bool is_prev_allowed; s32 cpu; preempt_disable(); /* + * Check whether @prev_cpu is still within the allowed set. If not, + * we can still try selecting a nearby CPU. + */ + is_prev_allowed = cpumask_test_cpu(prev_cpu, allowed); + + /* * Determine the subset of CPUs usable by @p within @cpus_allowed. */ if (allowed != p->cpus_ptr) { @@ -465,21 +480,6 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, cpu = -EBUSY; goto out_enable; } - - /* - * If @prev_cpu is not in the allowed CPUs, skip topology - * optimizations and try to pick any idle CPU usable by the - * task. - * - * If %SCX_OPS_BUILTIN_IDLE_PER_NODE is enabled, prioritize - * the current node, as it may optimize some waker->wakee - * workloads. - */ - if (!cpumask_test_cpu(prev_cpu, allowed)) { - node = scx_cpu_node_if_enabled(smp_processor_id()); - cpu = scx_pick_idle_cpu(allowed, node, flags); - goto out_enable; - } } /* @@ -525,7 +525,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, * then avoid a migration. */ cpu = smp_processor_id(); - if (cpus_share_cache(cpu, prev_cpu) && + if (is_prev_allowed && cpus_share_cache(cpu, prev_cpu) && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; @@ -562,7 +562,8 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, /* * Keep using @prev_cpu if it's part of a fully idle core. */ - if (cpumask_test_cpu(prev_cpu, idle_cpumask(node)->smt) && + if (is_prev_allowed && + cpumask_test_cpu(prev_cpu, idle_cpumask(node)->smt) && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; @@ -611,7 +612,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, /* * Use @prev_cpu if it's idle. */ - if (scx_idle_test_and_clear_cpu(prev_cpu)) { + if (is_prev_allowed && scx_idle_test_and_clear_cpu(prev_cpu)) { cpu = prev_cpu; goto out_unlock; } |