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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: d84dc1e1-45a5-4ffd-f7d7-08dd5046baa4 X-MS-Exchange-CrossTenant-AuthSource: CY5PR12MB6405.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Feb 2025 18:04:46.8398 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: PYRwvCd0/Pka8QvjZBRnA8My+CUZeb0wsezISzQ7A4uB8WJztQDqFn6n4iwms8Ks7BZ99X/AeStOoAtjjjWDNQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB6230 Introduce a new kfunc to retrieve the node associated to a CPU: int scx_bpf_cpu_node(s32 cpu) Add the following kfuncs to provide BPF schedulers direct access to per-node idle cpumasks information: const struct cpumask *scx_bpf_get_idle_cpumask_node(int node) const struct cpumask *scx_bpf_get_idle_smtmask_node(int node) s32 scx_bpf_pick_idle_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) s32 scx_bpf_pick_any_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) Moreover, trigger an scx error when any of the non-node aware idle CPU kfuncs are used when SCX_OPS_BUILTIN_IDLE_PER_NODE is enabled. Cc: Yury Norov [NVIDIA] Signed-off-by: Andrea Righi Reviewed-by: Yury Norov [NVIDIA] --- Changes (this was part of a previous patch set, already applied): - rename scx_bpf_pick_idle_cpu_in_node() -> scx_bpf_pick_idle_cpu_node() - rename scx_bpf_pick_any_cpu_in_node() -> scx_bpf_pick_idle_cpu_node() kernel/sched/ext_idle.c | 182 +++++++++++++++++++++++ tools/sched_ext/include/scx/common.bpf.h | 5 + tools/sched_ext/include/scx/compat.bpf.h | 31 ++++ 3 files changed, 218 insertions(+) diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 8dacccc82ed63..759a06774b5b3 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -728,6 +728,33 @@ void scx_idle_disable(void) /******************************************************************************** * Helpers that can be called from the BPF scheduler. */ + +static int validate_node(int node) +{ + if (!static_branch_likely(&scx_builtin_idle_per_node)) { + scx_ops_error("per-node idle tracking is disabled"); + return -EOPNOTSUPP; + } + + /* Return no entry for NUMA_NO_NODE (not a critical scx error) */ + if (node == NUMA_NO_NODE) + return -ENOENT; + + /* Make sure node is in a valid range */ + if (node < 0 || node >= nr_node_ids) { + scx_ops_error("invalid node %d", node); + return -EINVAL; + } + + /* Make sure the node is part of the set of possible nodes */ + if (!node_possible(node)) { + scx_ops_error("unavailable node %d", node); + return -EINVAL; + } + + return node; +} + __bpf_kfunc_start_defs(); static bool check_builtin_idle_enabled(void) @@ -739,6 +766,23 @@ static bool check_builtin_idle_enabled(void) return false; } +/** + * scx_bpf_cpu_node - Return the NUMA node the given @cpu belongs to, or + * trigger an error if @cpu is invalid + * @cpu: target CPU + */ +__bpf_kfunc int scx_bpf_cpu_node(s32 cpu) +{ +#ifdef CONFIG_NUMA + if (!ops_cpu_valid(cpu, NULL)) + return NUMA_NO_NODE; + + return cpu_to_node(cpu); +#else + return 0; +#endif +} + /** * scx_bpf_select_cpu_dfl - The default implementation of ops.select_cpu() * @p: task_struct to select a CPU for @@ -771,6 +815,28 @@ __bpf_kfunc s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, return prev_cpu; } +/** + * scx_bpf_get_idle_cpumask_node - Get a referenced kptr to the + * idle-tracking per-CPU cpumask of a target NUMA node. + * @node: target NUMA node + * + * Returns an empty cpumask if idle tracking is not enabled, if @node is + * not valid, or running on a UP kernel. In this case the actual error will + * be reported to the BPF scheduler via scx_ops_error(). + */ +__bpf_kfunc const struct cpumask *scx_bpf_get_idle_cpumask_node(int node) +{ + node = validate_node(node); + if (node < 0) + return cpu_none_mask; + +#ifdef CONFIG_SMP + return idle_cpumask(node)->cpu; +#else + return cpu_none_mask; +#endif +} + /** * scx_bpf_get_idle_cpumask - Get a referenced kptr to the idle-tracking * per-CPU cpumask. @@ -795,6 +861,32 @@ __bpf_kfunc const struct cpumask *scx_bpf_get_idle_cpumask(void) #endif } +/** + * scx_bpf_get_idle_smtmask_node - Get a referenced kptr to the + * idle-tracking, per-physical-core cpumask of a target NUMA node. Can be + * used to determine if an entire physical core is free. + * @node: target NUMA node + * + * Returns an empty cpumask if idle tracking is not enabled, if @node is + * not valid, or running on a UP kernel. In this case the actual error will + * be reported to the BPF scheduler via scx_ops_error(). + */ +__bpf_kfunc const struct cpumask *scx_bpf_get_idle_smtmask_node(int node) +{ + node = validate_node(node); + if (node < 0) + return cpu_none_mask; + +#ifdef CONFIG_SMP + if (sched_smt_active()) + return idle_cpumask(node)->smt; + else + return idle_cpumask(node)->cpu; +#else + return cpu_none_mask; +#endif +} + /** * scx_bpf_get_idle_smtmask - Get a referenced kptr to the idle-tracking, * per-physical-core cpumask. Can be used to determine if an entire physical @@ -859,6 +951,35 @@ __bpf_kfunc bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) return false; } +/** + * scx_bpf_pick_idle_cpu_node - Pick and claim an idle cpu from @node + * @cpus_allowed: Allowed cpumask + * @node: target NUMA node + * @flags: %SCX_PICK_IDLE_* flags + * + * Pick and claim an idle cpu in @cpus_allowed from the NUMA node @node. + * + * Returns the picked idle cpu number on success, or -%EBUSY if no matching + * cpu was found. + * + * The search starts from @node and proceeds to other online NUMA nodes in + * order of increasing distance (unless SCX_PICK_IDLE_IN_NODE is specified, + * in which case the search is limited to the target @node). + * + * Always returns an error if ops.update_idle() is implemented and + * %SCX_OPS_KEEP_BUILTIN_IDLE is not set, or if + * %SCX_OPS_BUILTIN_IDLE_PER_NODE is not set. + */ +__bpf_kfunc s32 scx_bpf_pick_idle_cpu_node(const struct cpumask *cpus_allowed, + int node, u64 flags) +{ + node = validate_node(node); + if (node < 0) + return node; + + return scx_pick_idle_cpu(cpus_allowed, node, flags); +} + /** * scx_bpf_pick_idle_cpu - Pick and claim an idle cpu * @cpus_allowed: Allowed cpumask @@ -877,16 +998,64 @@ __bpf_kfunc bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) * * Unavailable if ops.update_idle() is implemented and * %SCX_OPS_KEEP_BUILTIN_IDLE is not set. + * + * Always returns an error if %SCX_OPS_BUILTIN_IDLE_PER_NODE is set, use + * scx_bpf_pick_idle_cpu_node() instead. */ __bpf_kfunc s32 scx_bpf_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags) { + if (static_branch_maybe(CONFIG_NUMA, &scx_builtin_idle_per_node)) { + scx_ops_error("per-node idle tracking is enabled"); + return -EBUSY; + } + if (!check_builtin_idle_enabled()) return -EBUSY; return scx_pick_idle_cpu(cpus_allowed, NUMA_NO_NODE, flags); } +/** + * scx_bpf_pick_any_cpu_node - Pick and claim an idle cpu if available + * or pick any CPU from @node + * @cpus_allowed: Allowed cpumask + * @node: target NUMA node + * @flags: %SCX_PICK_IDLE_CPU_* flags + * + * Pick and claim an idle cpu in @cpus_allowed. If none is available, pick any + * CPU in @cpus_allowed. Guaranteed to succeed and returns the picked idle cpu + * number if @cpus_allowed is not empty. -%EBUSY is returned if @cpus_allowed is + * empty. + * + * The search starts from @node and proceeds to other online NUMA nodes in + * order of increasing distance (unless SCX_PICK_IDLE_IN_NODE is specified, + * in which case the search is limited to the target @node). + * + * If ops.update_idle() is implemented and %SCX_OPS_KEEP_BUILTIN_IDLE is not + * set, this function can't tell which CPUs are idle and will always pick any + * CPU. + */ +__bpf_kfunc s32 scx_bpf_pick_any_cpu_node(const struct cpumask *cpus_allowed, + int node, u64 flags) +{ + s32 cpu; + + node = validate_node(node); + if (node < 0) + return node; + + cpu = scx_pick_idle_cpu(cpus_allowed, node, flags); + if (cpu >= 0) + return cpu; + + cpu = cpumask_any_distribute(cpus_allowed); + if (cpu < nr_cpu_ids) + return cpu; + else + return -EBUSY; +} + /** * scx_bpf_pick_any_cpu - Pick and claim an idle cpu if available or pick any CPU * @cpus_allowed: Allowed cpumask @@ -900,12 +1069,20 @@ __bpf_kfunc s32 scx_bpf_pick_idle_cpu(const struct cpumask *cpus_allowed, * If ops.update_idle() is implemented and %SCX_OPS_KEEP_BUILTIN_IDLE is not * set, this function can't tell which CPUs are idle and will always pick any * CPU. + * + * Always returns an error if %SCX_OPS_BUILTIN_IDLE_PER_NODE is set, use + * scx_bpf_pick_any_cpu_node() instead. */ __bpf_kfunc s32 scx_bpf_pick_any_cpu(const struct cpumask *cpus_allowed, u64 flags) { s32 cpu; + if (static_branch_maybe(CONFIG_NUMA, &scx_builtin_idle_per_node)) { + scx_ops_error("per-node idle tracking is enabled"); + return -EBUSY; + } + if (static_branch_likely(&scx_builtin_idle_enabled)) { cpu = scx_pick_idle_cpu(cpus_allowed, NUMA_NO_NODE, flags); if (cpu >= 0) @@ -922,11 +1099,16 @@ __bpf_kfunc s32 scx_bpf_pick_any_cpu(const struct cpumask *cpus_allowed, __bpf_kfunc_end_defs(); BTF_KFUNCS_START(scx_kfunc_ids_idle) +BTF_ID_FLAGS(func, scx_bpf_cpu_node) +BTF_ID_FLAGS(func, scx_bpf_get_idle_cpumask_node, KF_ACQUIRE) BTF_ID_FLAGS(func, scx_bpf_get_idle_cpumask, KF_ACQUIRE) +BTF_ID_FLAGS(func, scx_bpf_get_idle_smtmask_node, KF_ACQUIRE) BTF_ID_FLAGS(func, scx_bpf_get_idle_smtmask, KF_ACQUIRE) BTF_ID_FLAGS(func, scx_bpf_put_idle_cpumask, KF_RELEASE) BTF_ID_FLAGS(func, scx_bpf_test_and_clear_cpu_idle) +BTF_ID_FLAGS(func, scx_bpf_pick_idle_cpu_node, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_pick_idle_cpu, KF_RCU) +BTF_ID_FLAGS(func, scx_bpf_pick_any_cpu_node, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_pick_any_cpu, KF_RCU) BTF_KFUNCS_END(scx_kfunc_ids_idle) diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index 77bbe0199a32c..ca7cc4108b45f 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -71,14 +71,19 @@ u32 scx_bpf_cpuperf_cap(s32 cpu) __ksym __weak; u32 scx_bpf_cpuperf_cur(s32 cpu) __ksym __weak; void scx_bpf_cpuperf_set(s32 cpu, u32 perf) __ksym __weak; u32 scx_bpf_nr_cpu_ids(void) __ksym __weak; +int scx_bpf_cpu_node(s32 cpu) __ksym __weak; const struct cpumask *scx_bpf_get_possible_cpumask(void) __ksym __weak; const struct cpumask *scx_bpf_get_online_cpumask(void) __ksym __weak; void scx_bpf_put_cpumask(const struct cpumask *cpumask) __ksym __weak; +const struct cpumask *scx_bpf_get_idle_cpumask_node(int node) __ksym __weak; const struct cpumask *scx_bpf_get_idle_cpumask(void) __ksym; +const struct cpumask *scx_bpf_get_idle_smtmask_node(int node) __ksym __weak; const struct cpumask *scx_bpf_get_idle_smtmask(void) __ksym; void scx_bpf_put_idle_cpumask(const struct cpumask *cpumask) __ksym; bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) __ksym; +s32 scx_bpf_pick_idle_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) __ksym __weak; s32 scx_bpf_pick_idle_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym; +s32 scx_bpf_pick_any_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags) __ksym __weak; s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym; bool scx_bpf_task_running(const struct task_struct *p) __ksym; s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym; diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h index e5fa72f9bf22b..2d9273f604ff7 100644 --- a/tools/sched_ext/include/scx/compat.bpf.h +++ b/tools/sched_ext/include/scx/compat.bpf.h @@ -182,6 +182,37 @@ static inline bool __COMPAT_is_enq_cpu_selected(u64 enq_flags) scx_bpf_now() : \ bpf_ktime_get_ns()) +/* + * + * v6.15: Introduce NUMA-aware kfuncs to operate with per-node idle + * cpumasks. + * + * Preserve the following __COMPAT_scx_*_node macros until v6.17. + */ +#define __COMPAT_scx_bpf_cpu_node(cpu) \ + (bpf_ksym_exists(scx_bpf_cpu_node) ? \ + scx_bpf_cpu_node(cpu) : 0) + +#define __COMPAT_scx_bpf_get_idle_cpumask_node(node) \ + (bpf_ksym_exists(scx_bpf_get_idle_cpumask_node) ? \ + scx_bpf_get_idle_cpumask_node(node) : \ + scx_bpf_get_idle_cpumask()) \ + +#define __COMPAT_scx_bpf_get_idle_smtmask_node(node) \ + (bpf_ksym_exists(scx_bpf_get_idle_smtmask_node) ? \ + scx_bpf_get_idle_smtmask_node(node) : \ + scx_bpf_get_idle_smtmask()) + +#define __COMPAT_scx_bpf_pick_idle_cpu_node(cpus_allowed, node, flags) \ + (bpf_ksym_exists(scx_bpf_pick_idle_cpu_node) ? \ + scx_bpf_pick_idle_cpu_node(cpus_allowed, node, flags) : \ + scx_bpf_pick_idle_cpu(cpus_allowed, flags)) + +#define __COMPAT_scx_bpf_pick_any_cpu_node(cpus_allowed, node, flags) \ + (bpf_ksym_exists(scx_bpf_pick_any_cpu_node) ? \ + scx_bpf_pick_any_cpu_node(cpus_allowed, node, flags) : \ + scx_bpf_pick_any_cpu(cpus_allowed, flags)) + /* * Define sched_ext_ops. This may be expanded to define multiple variants for * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().