On Fri, Feb 14, 2025 at 08:40:06PM +0100, Andrea Righi wrote: > Using a single global idle mask can lead to inefficiencies and a lot of > stress on the cache coherency protocol on large systems with multiple > NUMA nodes, since all the CPUs can create a really intense read/write > activity on the single global cpumask. > > Therefore, split the global cpumask into multiple per-NUMA node cpumasks > to improve scalability and performance on large systems. > > The concept is that each cpumask will track only the idle CPUs within > its corresponding NUMA node, treating CPUs in other NUMA nodes as busy. > In this way concurrent access to the idle cpumask will be restricted > within each NUMA node. > > The split of multiple per-node idle cpumasks can be controlled using the > SCX_OPS_BUILTIN_IDLE_PER_NODE flag. > > By default SCX_OPS_BUILTIN_IDLE_PER_NODE is not enabled and a global > host-wide idle cpumask is used, maintaining the previous behavior. > > NOTE: if a scheduler explicitly enables the per-node idle cpumasks (via > SCX_OPS_BUILTIN_IDLE_PER_NODE), scx_bpf_get_idle_cpu/smtmask() will > trigger an scx error, since there are no system-wide cpumasks. > > = Test = > > Hardware: > - System: DGX B200 > - CPUs: 224 SMT threads (112 physical cores) > - Processor: INTEL(R) XEON(R) PLATINUM 8570 > - 2 NUMA nodes > > Scheduler: > - scx_simple [1] (so that we can focus at the built-in idle selection > policy and not at the scheduling policy itself) > > Test: > - Run a parallel kernel build `make -j $(nproc)` and measure the average > elapsed time over 10 runs: > > avg time | stdev > ---------+------ > before: 52.431s | 2.895 > after: 50.342s | 2.895 > > = Conclusion = > > Splitting the global cpumask into multiple per-NUMA cpumasks helped to > achieve a speedup of approximately +4% with this particular architecture > and test case. > > The same test on a DGX-1 (40 physical cores, Intel Xeon E5-2698 v4 @ > 2.20GHz, 2 NUMA nodes) shows a speedup of around 1.5-3%. > > On smaller systems, I haven't noticed any measurable regressions or > improvements with the same test (parallel kernel build) and scheduler > (scx_simple). > > Moreover, with a modified scx_bpfland that uses the new NUMA-aware APIs > I observed an additional +2-2.5% performance improvement with the same > test. > > [1] https://github.com/sched-ext/scx/blob/main/scheds/c/scx_simple.bpf.c > > Cc: Yury Norov [NVIDIA] <yury.norov@xxxxxxxxx> > Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx> Reviewed-by: Yury Norov [NVIDIA] <yury.norov@xxxxxxxxx> > --- > kernel/sched/ext.c | 1 + > kernel/sched/ext_idle.c | 283 ++++++++++++++++++++++----- > kernel/sched/ext_idle.h | 4 +- > tools/sched_ext/include/scx/compat.h | 3 + > 4 files changed, 236 insertions(+), 55 deletions(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 330a359d79301..95603db36f043 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -806,6 +806,7 @@ enum scx_deq_flags { > > enum scx_pick_idle_cpu_flags { > SCX_PICK_IDLE_CORE = 1LLU << 0, /* pick a CPU whose SMT siblings are also idle */ > + SCX_PICK_IDLE_IN_NODE = 1LLU << 1, /* pick a CPU in the same target NUMA node */ > }; > > enum scx_kick_flags { > diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c > index 0912f94b95cdc..8dacccc82ed63 100644 > --- a/kernel/sched/ext_idle.c > +++ b/kernel/sched/ext_idle.c > @@ -18,25 +18,61 @@ static DEFINE_STATIC_KEY_FALSE(scx_builtin_idle_enabled); > static DEFINE_STATIC_KEY_FALSE(scx_builtin_idle_per_node); > > #ifdef CONFIG_SMP > -#ifdef CONFIG_CPUMASK_OFFSTACK > -#define CL_ALIGNED_IF_ONSTACK > -#else > -#define CL_ALIGNED_IF_ONSTACK __cacheline_aligned_in_smp > -#endif > - > /* Enable/disable LLC aware optimizations */ > static DEFINE_STATIC_KEY_FALSE(scx_selcpu_topo_llc); > > /* Enable/disable NUMA aware optimizations */ > static DEFINE_STATIC_KEY_FALSE(scx_selcpu_topo_numa); > > -static struct { > +/* > + * cpumasks to track idle CPUs within each NUMA node. > + * > + * If SCX_OPS_BUILTIN_IDLE_PER_NODE is not enabled, a single global cpumask > + * from is used to track all the idle CPUs in the system. > + */ > +struct scx_idle_cpus { > cpumask_var_t cpu; > cpumask_var_t smt; > -} idle_masks CL_ALIGNED_IF_ONSTACK; > +}; > + > +/* > + * Global host-wide idle cpumasks (used when SCX_OPS_BUILTIN_IDLE_PER_NODE > + * is not enabled). > + */ > +static struct scx_idle_cpus scx_idle_global_masks; > + > +/* > + * Per-node idle cpumasks. > + */ > +static struct scx_idle_cpus **scx_idle_node_masks; > + > +/* > + * Return the idle masks associated to a target @node. > + * > + * NUMA_NO_NODE identifies the global idle cpumask. > + */ > +static struct scx_idle_cpus *idle_cpumask(int node) > +{ > + return node == NUMA_NO_NODE ? &scx_idle_global_masks : scx_idle_node_masks[node]; > +} > + > +/* > + * Returns the NUMA node ID associated with a @cpu, or NUMA_NO_NODE if > + * per-node idle cpumasks are disabled. > + */ > +static int scx_cpu_node_if_enabled(int cpu) > +{ > + if (!static_branch_maybe(CONFIG_NUMA, &scx_builtin_idle_per_node)) > + return NUMA_NO_NODE; > + > + return cpu_to_node(cpu); > +} > > bool scx_idle_test_and_clear_cpu(int cpu) > { > + int node = scx_cpu_node_if_enabled(cpu); > + struct cpumask *idle_cpus = idle_cpumask(node)->cpu; > + > #ifdef CONFIG_SCHED_SMT > /* > * SMT mask should be cleared whether we can claim @cpu or not. The SMT > @@ -45,33 +81,38 @@ bool scx_idle_test_and_clear_cpu(int cpu) > */ > if (sched_smt_active()) { > const struct cpumask *smt = cpu_smt_mask(cpu); > + struct cpumask *idle_smts = idle_cpumask(node)->smt; > > /* > * If offline, @cpu is not its own sibling and > * scx_pick_idle_cpu() can get caught in an infinite loop as > - * @cpu is never cleared from idle_masks.smt. Ensure that @cpu > - * is eventually cleared. > + * @cpu is never cleared from the idle SMT mask. Ensure that > + * @cpu is eventually cleared. > * > * NOTE: Use cpumask_intersects() and cpumask_test_cpu() to > * reduce memory writes, which may help alleviate cache > * coherence pressure. > */ > - if (cpumask_intersects(smt, idle_masks.smt)) > - cpumask_andnot(idle_masks.smt, idle_masks.smt, smt); > - else if (cpumask_test_cpu(cpu, idle_masks.smt)) > - __cpumask_clear_cpu(cpu, idle_masks.smt); > + if (cpumask_intersects(smt, idle_smts)) > + cpumask_andnot(idle_smts, idle_smts, smt); > + else if (cpumask_test_cpu(cpu, idle_smts)) > + __cpumask_clear_cpu(cpu, idle_smts); > } > #endif > - return cpumask_test_and_clear_cpu(cpu, idle_masks.cpu); > + > + return cpumask_test_and_clear_cpu(cpu, idle_cpus); > } > > -s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags) > +/* > + * Pick an idle CPU in a specific NUMA node. > + */ > +static s32 pick_idle_cpu_in_node(const struct cpumask *cpus_allowed, int node, u64 flags) > { > int cpu; > > retry: > if (sched_smt_active()) { > - cpu = cpumask_any_and_distribute(idle_masks.smt, cpus_allowed); > + cpu = cpumask_any_and_distribute(idle_cpumask(node)->smt, cpus_allowed); > if (cpu < nr_cpu_ids) > goto found; > > @@ -79,7 +120,7 @@ s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags) > return -EBUSY; > } > > - cpu = cpumask_any_and_distribute(idle_masks.cpu, cpus_allowed); > + cpu = cpumask_any_and_distribute(idle_cpumask(node)->cpu, cpus_allowed); > if (cpu >= nr_cpu_ids) > return -EBUSY; > > @@ -90,6 +131,85 @@ s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags) > goto retry; > } > > +/* > + * Tracks nodes that have not yet been visited when searching for an idle > + * CPU across all available nodes. > + */ > +static DEFINE_PER_CPU(nodemask_t, per_cpu_unvisited); > + > +/* > + * Search for an idle CPU across all nodes, excluding @node. > + */ > +static s32 pick_idle_cpu_from_online_nodes(const struct cpumask *cpus_allowed, int node, u64 flags) > +{ > + nodemask_t *unvisited; > + s32 cpu = -EBUSY; > + > + preempt_disable(); > + unvisited = this_cpu_ptr(&per_cpu_unvisited); > + > + /* > + * Restrict the search to the online nodes (excluding the current > + * node that has been visited already). > + */ > + nodes_copy(*unvisited, node_states[N_ONLINE]); > + node_clear(node, *unvisited); > + > + /* > + * Traverse all nodes in order of increasing distance, starting > + * from @node. > + * > + * This loop is O(N^2), with N being the amount of NUMA nodes, > + * which might be quite expensive in large NUMA systems. However, > + * this complexity comes into play only when a scheduler enables > + * SCX_OPS_BUILTIN_IDLE_PER_NODE and it's requesting an idle CPU > + * without specifying a target NUMA node, so it shouldn't be a > + * bottleneck is most cases. > + * > + * As a future optimization we may want to cache the list of nodes > + * in a per-node array, instead of actually traversing them every > + * time. > + */ > + for_each_node_numadist(node, *unvisited) { > + cpu = pick_idle_cpu_in_node(cpus_allowed, node, flags); > + if (cpu >= 0) > + break; > + } > + preempt_enable(); > + > + return cpu; > +} > + > +/* > + * Find an idle CPU in the system, starting from @node. > + */ > +s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, int node, u64 flags) > +{ > + s32 cpu; > + > + /* > + * Always search in the starting node first (this is an > + * optimization that can save some cycles even when the search is > + * not limited to a single node). > + */ > + cpu = pick_idle_cpu_in_node(cpus_allowed, node, flags); > + if (cpu >= 0) > + return cpu; > + > + /* > + * Stop the search if we are using only a single global cpumask > + * (NUMA_NO_NODE) or if the search is restricted to the first node > + * only. > + */ > + if (node == NUMA_NO_NODE || flags & SCX_PICK_IDLE_IN_NODE) > + return -EBUSY; > + > + /* > + * Extend the search to the other online nodes. > + */ > + return pick_idle_cpu_from_online_nodes(cpus_allowed, node, flags); > +} > + > /* > * Return the amount of CPUs in the same LLC domain of @cpu (or zero if the LLC > * domain is not defined). > @@ -302,6 +422,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > { > const struct cpumask *llc_cpus = NULL; > const struct cpumask *numa_cpus = NULL; > + int node = scx_cpu_node_if_enabled(prev_cpu); > s32 cpu; > > *found = false; > @@ -359,9 +480,9 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > * piled up on it even if there is an idle core elsewhere on > * the system. > */ > - if (!cpumask_empty(idle_masks.cpu) && > - !(current->flags & PF_EXITING) && > - cpu_rq(cpu)->scx.local_dsq.nr == 0) { > + if (!(current->flags & PF_EXITING) && > + cpu_rq(cpu)->scx.local_dsq.nr == 0 && > + !cpumask_empty(idle_cpumask(cpu_to_node(cpu))->cpu)) { > if (cpumask_test_cpu(cpu, p->cpus_ptr)) > goto cpu_found; > } > @@ -375,7 +496,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > /* > * Keep using @prev_cpu if it's part of a fully idle core. > */ > - if (cpumask_test_cpu(prev_cpu, idle_masks.smt) && > + if (cpumask_test_cpu(prev_cpu, idle_cpumask(node)->smt) && > scx_idle_test_and_clear_cpu(prev_cpu)) { > cpu = prev_cpu; > goto cpu_found; > @@ -385,7 +506,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > * Search for any fully idle core in the same LLC domain. > */ > if (llc_cpus) { > - cpu = scx_pick_idle_cpu(llc_cpus, SCX_PICK_IDLE_CORE); > + cpu = pick_idle_cpu_in_node(llc_cpus, node, SCX_PICK_IDLE_CORE); > if (cpu >= 0) > goto cpu_found; > } > @@ -394,15 +515,19 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > * Search for any fully idle core in the same NUMA node. > */ > if (numa_cpus) { > - cpu = scx_pick_idle_cpu(numa_cpus, SCX_PICK_IDLE_CORE); > + cpu = pick_idle_cpu_in_node(numa_cpus, node, SCX_PICK_IDLE_CORE); > if (cpu >= 0) > goto cpu_found; > } > > /* > * Search for any full idle core usable by the task. > + * > + * If NUMA aware idle selection is enabled, the search will > + * begin in prev_cpu's node and proceed to other nodes in > + * order of increasing distance. > */ > - cpu = scx_pick_idle_cpu(p->cpus_ptr, SCX_PICK_IDLE_CORE); > + cpu = scx_pick_idle_cpu(p->cpus_ptr, node, SCX_PICK_IDLE_CORE); > if (cpu >= 0) > goto cpu_found; > } > @@ -419,7 +544,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > * Search for any idle CPU in the same LLC domain. > */ > if (llc_cpus) { > - cpu = scx_pick_idle_cpu(llc_cpus, 0); > + cpu = pick_idle_cpu_in_node(llc_cpus, node, 0); > if (cpu >= 0) > goto cpu_found; > } > @@ -428,7 +553,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > * Search for any idle CPU in the same NUMA node. > */ > if (numa_cpus) { > - cpu = scx_pick_idle_cpu(numa_cpus, 0); > + cpu = pick_idle_cpu_in_node(numa_cpus, node, 0); > if (cpu >= 0) > goto cpu_found; > } > @@ -436,7 +561,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > /* > * Search for any idle CPU usable by the task. > */ > - cpu = scx_pick_idle_cpu(p->cpus_ptr, 0); > + cpu = scx_pick_idle_cpu(p->cpus_ptr, node, 0); > if (cpu >= 0) > goto cpu_found; > > @@ -450,30 +575,54 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool > return cpu; > } > > +/* > + * Initialize global and per-node idle cpumasks. > + */ > void scx_idle_init_masks(void) > { > - BUG_ON(!alloc_cpumask_var(&idle_masks.cpu, GFP_KERNEL)); > - BUG_ON(!alloc_cpumask_var(&idle_masks.smt, GFP_KERNEL)); > + int node; > + > + /* Allocate global idle cpumasks */ > + BUG_ON(!alloc_cpumask_var(&scx_idle_global_masks.cpu, GFP_KERNEL)); > + BUG_ON(!alloc_cpumask_var(&scx_idle_global_masks.smt, GFP_KERNEL)); > + > + /* Allocate per-node idle cpumasks */ > + scx_idle_node_masks = kcalloc(num_possible_nodes(), > + sizeof(*scx_idle_node_masks), GFP_KERNEL); > + BUG_ON(!scx_idle_node_masks); > + > + for_each_node(node) { > + scx_idle_node_masks[node] = kzalloc_node(sizeof(**scx_idle_node_masks), > + GFP_KERNEL, node); > + BUG_ON(!scx_idle_node_masks[node]); > + > + BUG_ON(!alloc_cpumask_var_node(&scx_idle_node_masks[node]->cpu, GFP_KERNEL, node)); > + BUG_ON(!alloc_cpumask_var_node(&scx_idle_node_masks[node]->smt, GFP_KERNEL, node)); > + } > } > > static void update_builtin_idle(int cpu, bool idle) > { > - assign_cpu(cpu, idle_masks.cpu, idle); > + int node = scx_cpu_node_if_enabled(cpu); > + struct cpumask *idle_cpus = idle_cpumask(node)->cpu; > + > + assign_cpu(cpu, idle_cpus, idle); > > #ifdef CONFIG_SCHED_SMT > if (sched_smt_active()) { > const struct cpumask *smt = cpu_smt_mask(cpu); > + struct cpumask *idle_smts = idle_cpumask(node)->smt; > > if (idle) { > /* > - * idle_masks.smt handling is racy but that's fine as > - * it's only for optimization and self-correcting. > + * idle_smt handling is racy but that's fine as it's > + * only for optimization and self-correcting. > */ > - if (!cpumask_subset(smt, idle_masks.cpu)) > + if (!cpumask_subset(smt, idle_cpus)) > return; > - cpumask_or(idle_masks.smt, idle_masks.smt, smt); > + cpumask_or(idle_smts, idle_smts, smt); > } else { > - cpumask_andnot(idle_masks.smt, idle_masks.smt, smt); > + cpumask_andnot(idle_smts, idle_smts, smt); > } > } > #endif > @@ -529,15 +678,36 @@ void __scx_update_idle(struct rq *rq, bool idle, bool do_notify) > if (do_notify || is_idle_task(rq->curr)) > update_builtin_idle(cpu, idle); > } > + > +static void reset_idle_masks(struct sched_ext_ops *ops) > +{ > + int node; > + > + /* > + * Consider all online cpus idle. Should converge to the actual state > + * quickly. > + */ > + if (!(ops->flags & SCX_OPS_BUILTIN_IDLE_PER_NODE)) { > + cpumask_copy(idle_cpumask(NUMA_NO_NODE)->cpu, cpu_online_mask); > + cpumask_copy(idle_cpumask(NUMA_NO_NODE)->smt, cpu_online_mask); > + return; > + } > + > + for_each_node(node) { > + const struct cpumask *node_mask = cpumask_of_node(node); > + > + cpumask_and(idle_cpumask(node)->cpu, cpu_online_mask, node_mask); > + cpumask_and(idle_cpumask(node)->smt, cpu_online_mask, node_mask); > + } > +} > #endif /* CONFIG_SMP */ > > void scx_idle_enable(struct sched_ext_ops *ops) > { > - if (ops->update_idle && !(ops->flags & SCX_OPS_KEEP_BUILTIN_IDLE)) { > + if (!ops->update_idle || (ops->flags & SCX_OPS_KEEP_BUILTIN_IDLE)) > + static_branch_enable(&scx_builtin_idle_enabled); > + else > static_branch_disable(&scx_builtin_idle_enabled); > - return; > - } > - static_branch_enable(&scx_builtin_idle_enabled); > > if (ops->flags & SCX_OPS_BUILTIN_IDLE_PER_NODE) > static_branch_enable(&scx_builtin_idle_per_node); > @@ -545,12 +715,7 @@ void scx_idle_enable(struct sched_ext_ops *ops) > static_branch_disable(&scx_builtin_idle_per_node); > > #ifdef CONFIG_SMP > - /* > - * Consider all online cpus idle. Should converge to the actual state > - * quickly. > - */ > - cpumask_copy(idle_masks.cpu, cpu_online_mask); > - cpumask_copy(idle_masks.smt, cpu_online_mask); > + reset_idle_masks(ops); > #endif > } > > @@ -610,15 +775,21 @@ __bpf_kfunc s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, > * scx_bpf_get_idle_cpumask - Get a referenced kptr to the idle-tracking > * per-CPU cpumask. > * > - * Returns NULL if idle tracking is not enabled, or running on a UP kernel. > + * Returns an empty mask if idle tracking is not enabled, or running on a > + * UP kernel. > */ > __bpf_kfunc const struct cpumask *scx_bpf_get_idle_cpumask(void) > { > + if (static_branch_unlikely(&scx_builtin_idle_per_node)) { > + scx_ops_error("SCX_OPS_BUILTIN_IDLE_PER_NODE enabled"); > + return cpu_none_mask; > + } > + > if (!check_builtin_idle_enabled()) > return cpu_none_mask; > > #ifdef CONFIG_SMP > - return idle_masks.cpu; > + return idle_cpumask(NUMA_NO_NODE)->cpu; > #else > return cpu_none_mask; > #endif > @@ -629,18 +800,24 @@ __bpf_kfunc const struct cpumask *scx_bpf_get_idle_cpumask(void) > * per-physical-core cpumask. Can be used to determine if an entire physical > * core is free. > * > - * Returns NULL if idle tracking is not enabled, or running on a UP kernel. > + * Returns an empty mask if idle tracking is not enabled, or running on a > + * UP kernel. > */ > __bpf_kfunc const struct cpumask *scx_bpf_get_idle_smtmask(void) > { > + if (static_branch_unlikely(&scx_builtin_idle_per_node)) { > + scx_ops_error("SCX_OPS_BUILTIN_IDLE_PER_NODE enabled"); > + return cpu_none_mask; > + } > + > if (!check_builtin_idle_enabled()) > return cpu_none_mask; > > #ifdef CONFIG_SMP > if (sched_smt_active()) > - return idle_masks.smt; > + return idle_cpumask(NUMA_NO_NODE)->smt; > else > - return idle_masks.cpu; > + return idle_cpumask(NUMA_NO_NODE)->cpu; > #else > return cpu_none_mask; > #endif > @@ -707,7 +884,7 @@ __bpf_kfunc s32 scx_bpf_pick_idle_cpu(const struct cpumask *cpus_allowed, > if (!check_builtin_idle_enabled()) > return -EBUSY; > > - return scx_pick_idle_cpu(cpus_allowed, flags); > + return scx_pick_idle_cpu(cpus_allowed, NUMA_NO_NODE, flags); > } > > /** > @@ -730,7 +907,7 @@ __bpf_kfunc s32 scx_bpf_pick_any_cpu(const struct cpumask *cpus_allowed, > s32 cpu; > > if (static_branch_likely(&scx_builtin_idle_enabled)) { > - cpu = scx_pick_idle_cpu(cpus_allowed, flags); > + cpu = scx_pick_idle_cpu(cpus_allowed, NUMA_NO_NODE, flags); > if (cpu >= 0) > return cpu; > } > diff --git a/kernel/sched/ext_idle.h b/kernel/sched/ext_idle.h > index 339b6ec9c4cb7..68c4307ce4f6f 100644 > --- a/kernel/sched/ext_idle.h > +++ b/kernel/sched/ext_idle.h > @@ -16,12 +16,12 @@ struct sched_ext_ops; > void scx_idle_update_selcpu_topology(struct sched_ext_ops *ops); > void scx_idle_init_masks(void); > bool scx_idle_test_and_clear_cpu(int cpu); > -s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags); > +s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, int node, u64 flags); > #else /* !CONFIG_SMP */ > static inline void scx_idle_update_selcpu_topology(struct sched_ext_ops *ops) {} > static inline void scx_idle_init_masks(void) {} > static inline bool scx_idle_test_and_clear_cpu(int cpu) { return false; } > -static inline s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags) > +static inline s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, int node, u64 flags) > { > return -EBUSY; > } > diff --git a/tools/sched_ext/include/scx/compat.h b/tools/sched_ext/include/scx/compat.h > index d63cf40be8eee..03e06bd15c738 100644 > --- a/tools/sched_ext/include/scx/compat.h > +++ b/tools/sched_ext/include/scx/compat.h > @@ -112,6 +112,9 @@ static inline bool __COMPAT_struct_has_field(const char *type, const char *field > #define SCX_OPS_BUILTIN_IDLE_PER_NODE \ > __COMPAT_ENUM_OR_ZERO("scx_ops_flags", "SCX_OPS_BUILTIN_IDLE_PER_NODE") > > +#define SCX_PICK_IDLE_IN_NODE \ > + __COMPAT_ENUM_OR_ZERO("scx_pick_idle_cpu_flags", "SCX_PICK_IDLE_IN_NODE") > + > static inline long scx_hotplug_seq(void) > { > int fd; > -- > 2.48.1
