From: Tejun Heo <tj@kernel.org> mainline inclusion from mainline-v6.12-rc1 commit 60c27fb59f6cffa73fc8c60e3a22323c78044576 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- Add ops.cpu_online/offline() which are invoked when CPUs come online and offline respectively. As the enqueue path already automatically bypasses tasks to the local dsq on a deactivated CPU, BPF schedulers are guaranteed to see tasks only on CPUs which are between online() and offline(). If the BPF scheduler doesn't implement ops.cpu_online/offline(), the scheduler is automatically exited with SCX_ECODE_RESTART | SCX_ECODE_RSN_HOTPLUG. Userspace can implement CPU hotpplug support trivially by simply reinitializing and reloading the scheduler. scx_qmap is updated to print out online CPUs on hotplug events. Other schedulers are updated to restart based on ecode. v3: - The previous implementation added @reason to sched_class.rq_on/offline() to distinguish between CPU hotplug events and topology updates. This was buggy and fragile as the methods are skipped if the current state equals the target state. Instead, add scx_rq_[de]activate() which are directly called from sched_cpu_de/activate(). This also allows ops.cpu_on/offline() to sleep which can be useful. - ops.dispatch() could be called on a CPU that the BPF scheduler was told to be offline. The dispatch patch is updated to bypass in such cases. v2: - To accommodate lock ordering change between scx_cgroup_rwsem and cpus_read_lock(), CPU hotplug operations are put into its own SCX_OPI block and enabled eariler during scx_ope_enable() so that cpus_read_lock() can be dropped before acquiring scx_cgroup_rwsem. - Auto exit with ECODE added. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: David Vernet <dvernet@meta.com> Acked-by: Josh Don <joshdon@google.com> Acked-by: Hao Luo <haoluo@google.com> Acked-by: Barret Rhoden <brho@google.com> Conflicts: kernel/sched/core.c [Only pick the part modified by this mainline commit, and ignore the conflict part caused by higher version.] Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Signed-off-by: cheliequan <cheliequan@inspur.com> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/sched/core.c | 4 + kernel/sched/ext.c | 156 ++++++++++++++++++- kernel/sched/ext.h | 4 + kernel/sched/sched.h | 6 + tools/sched_ext/include/scx/compat.h | 26 ++++ tools/sched_ext/include/scx/user_exit_info.h | 28 ++++ tools/sched_ext/scx_central.c | 9 +- tools/sched_ext/scx_qmap.bpf.c | 57 +++++++ tools/sched_ext/scx_qmap.c | 4 + tools/sched_ext/scx_simple.c | 8 +- 10 files changed, 290 insertions(+), 12 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1084bb7609c0..9358cf97f7d2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7999,6 +7999,8 @@ int sched_cpu_activate(unsigned int cpu) cpuset_cpu_active(); } + scx_rq_activate(rq); + /* * Put the rq online, if not already. This happens: * @@ -8059,6 +8061,8 @@ int sched_cpu_deactivate(unsigned int cpu) } rq_unlock_irqrestore(rq, &rf); + scx_rq_deactivate(rq); + /* * When going down, decrement the number of cores with SMT present. */ diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 956d8cfad948..f1d1cac9b4f2 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -34,6 +34,29 @@ enum scx_exit_kind { SCX_EXIT_ERROR_STALL, /* watchdog detected stalled runnable tasks */ }; +/* + * An exit code can be specified when exiting with scx_bpf_exit() or + * scx_ops_exit(), corresponding to exit_kind UNREG_BPF and UNREG_KERN + * respectively. The codes are 64bit of the format: + * + * Bits: [63 .. 48 47 .. 32 31 .. 0] + * [ SYS ACT ] [ SYS RSN ] [ USR ] + * + * SYS ACT: System-defined exit actions + * SYS RSN: System-defined exit reasons + * USR : User-defined exit codes and reasons + * + * Using the above, users may communicate intention and context by ORing system + * actions and/or system reasons with a user-defined exit code. + */ +enum scx_exit_code { + /* Reasons */ + SCX_ECODE_RSN_HOTPLUG = 1LLU << 32, + + /* Actions */ + SCX_ECODE_ACT_RESTART = 1LLU << 48, +}; + /* * scx_exit_info is passed to ops.exit() to describe why the BPF scheduler is * being disabled. @@ -461,7 +484,29 @@ struct sched_ext_ops { void (*dump_task)(struct scx_dump_ctx *ctx, struct task_struct *p); /* - * All online ops must come before ops.init(). + * All online ops must come before ops.cpu_online(). + */ + + /** + * cpu_online - A CPU became online + * @cpu: CPU which just came up + * + * @cpu just came online. @cpu will not call ops.enqueue() or + * ops.dispatch(), nor run tasks associated with other CPUs beforehand. + */ + void (*cpu_online)(s32 cpu); + + /** + * cpu_offline - A CPU is going offline + * @cpu: CPU which is going offline + * + * @cpu is going offline. @cpu will not call ops.enqueue() or + * ops.dispatch(), nor run tasks associated with other CPUs afterwards. + */ + void (*cpu_offline)(s32 cpu); + + /* + * All CPU hotplug ops must come before ops.init(). */ /** @@ -500,6 +545,15 @@ struct sched_ext_ops { */ u32 exit_dump_len; + /** + * hotplug_seq - A sequence number that may be set by the scheduler to + * detect when a hotplug event has occurred during the loading process. + * If 0, no detection occurs. Otherwise, the scheduler will fail to + * load if the sequence number does not match @scx_hotplug_seq on the + * enable path. + */ + u64 hotplug_seq; + /** * name - BPF scheduler's name * @@ -513,7 +567,9 @@ struct sched_ext_ops { enum scx_opi { SCX_OPI_BEGIN = 0, SCX_OPI_NORMAL_BEGIN = 0, - SCX_OPI_NORMAL_END = SCX_OP_IDX(init), + SCX_OPI_NORMAL_END = SCX_OP_IDX(cpu_online), + SCX_OPI_CPU_HOTPLUG_BEGIN = SCX_OP_IDX(cpu_online), + SCX_OPI_CPU_HOTPLUG_END = SCX_OP_IDX(init), SCX_OPI_END = SCX_OP_IDX(init), }; @@ -698,6 +754,7 @@ static atomic_t scx_exit_kind = ATOMIC_INIT(SCX_EXIT_DONE); static struct scx_exit_info *scx_exit_info; static atomic_long_t scx_nr_rejected = ATOMIC_LONG_INIT(0); +static atomic_long_t scx_hotplug_seq = ATOMIC_LONG_INIT(0); /* * The maximum amount of time in jiffies that a task may be runnable without @@ -1423,11 +1480,7 @@ static void direct_dispatch(struct task_struct *p, u64 enq_flags) static bool scx_rq_online(struct rq *rq) { -#ifdef CONFIG_SMP - return likely(rq->online); -#else - return true; -#endif + return likely(rq->scx.flags & SCX_RQ_ONLINE); } static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags, @@ -1442,6 +1495,11 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags, if (sticky_cpu == cpu_of(rq)) goto local_norefill; + /* + * If !scx_rq_online(), we already told the BPF scheduler that the CPU + * is offline and are just running the hotplug path. Don't bother the + * BPF scheduler. + */ if (!scx_rq_online(rq)) goto local; @@ -2678,6 +2736,42 @@ void __scx_update_idle(struct rq *rq, bool idle) #endif } +static void handle_hotplug(struct rq *rq, bool online) +{ + int cpu = cpu_of(rq); + + atomic_long_inc(&scx_hotplug_seq); + + if (online && SCX_HAS_OP(cpu_online)) + SCX_CALL_OP(SCX_KF_SLEEPABLE, cpu_online, cpu); + else if (!online && SCX_HAS_OP(cpu_offline)) + SCX_CALL_OP(SCX_KF_SLEEPABLE, cpu_offline, cpu); + else + scx_ops_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG, + "cpu %d going %s, exiting scheduler", cpu, + online ? "online" : "offline"); +} + +void scx_rq_activate(struct rq *rq) +{ + handle_hotplug(rq, true); +} + +void scx_rq_deactivate(struct rq *rq) +{ + handle_hotplug(rq, false); +} + +static void rq_online_scx(struct rq *rq) +{ + rq->scx.flags |= SCX_RQ_ONLINE; +} + +static void rq_offline_scx(struct rq *rq) +{ + rq->scx.flags &= ~SCX_RQ_ONLINE; +} + #else /* CONFIG_SMP */ static bool test_and_clear_cpu_idle(int cpu) { return false; } @@ -3109,6 +3203,9 @@ DEFINE_SCHED_CLASS(ext) = { .balance = balance_scx, .select_task_rq = select_task_rq_scx, .set_cpus_allowed = set_cpus_allowed_scx, + + .rq_online = rq_online_scx, + .rq_offline = rq_offline_scx, #endif .task_tick = task_tick_scx, @@ -3240,10 +3337,18 @@ static ssize_t scx_attr_nr_rejected_show(struct kobject *kobj, } SCX_ATTR(nr_rejected); +static ssize_t scx_attr_hotplug_seq_show(struct kobject *kobj, + struct kobj_attribute *ka, char *buf) +{ + return sysfs_emit(buf, "%ld\n", atomic_long_read(&scx_hotplug_seq)); +} +SCX_ATTR(hotplug_seq); + static struct attribute *scx_global_attrs[] = { &scx_attr_state.attr, &scx_attr_switch_all.attr, &scx_attr_nr_rejected.attr, + &scx_attr_hotplug_seq.attr, NULL, }; @@ -3946,6 +4051,25 @@ static struct kthread_worker *scx_create_rt_helper(const char *name) return helper; } +static void check_hotplug_seq(const struct sched_ext_ops *ops) +{ + unsigned long long global_hotplug_seq; + + /* + * If a hotplug event has occurred between when a scheduler was + * initialized, and when we were able to attach, exit and notify user + * space about it. + */ + if (ops->hotplug_seq) { + global_hotplug_seq = atomic_long_read(&scx_hotplug_seq); + if (ops->hotplug_seq != global_hotplug_seq) { + scx_ops_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG, + "expected hotplug seq %llu did not match actual %llu", + ops->hotplug_seq, global_hotplug_seq); + } + } +} + static int validate_ops(const struct sched_ext_ops *ops) { /* @@ -4028,6 +4152,10 @@ static int scx_ops_enable(struct sched_ext_ops *ops) } } + for (i = SCX_OPI_CPU_HOTPLUG_BEGIN; i < SCX_OPI_CPU_HOTPLUG_END; i++) + if (((void (**)(void))ops)[i]) + static_branch_enable_cpuslocked(&scx_has_op[i]); + cpus_read_unlock(); ret = validate_ops(ops); @@ -4069,6 +4197,8 @@ static int scx_ops_enable(struct sched_ext_ops *ops) percpu_down_write(&scx_fork_rwsem); cpus_read_lock(); + check_hotplug_seq(ops); + for (i = SCX_OPI_NORMAL_BEGIN; i < SCX_OPI_NORMAL_END; i++) if (((void (**)(void))ops)[i]) static_branch_enable_cpuslocked(&scx_has_op[i]); @@ -4379,6 +4509,9 @@ static int bpf_scx_init_member(const struct btf_type *t, ops->exit_dump_len = *(u32 *)(udata + moff) ?: SCX_EXIT_DUMP_DFL_LEN; return 1; + case offsetof(struct sched_ext_ops, hotplug_seq): + ops->hotplug_seq = *(u64 *)(udata + moff); + return 1; } return 0; @@ -4392,6 +4525,8 @@ static int bpf_scx_check_member(const struct btf_type *t, switch (moff) { case offsetof(struct sched_ext_ops, init_task): + case offsetof(struct sched_ext_ops, cpu_online): + case offsetof(struct sched_ext_ops, cpu_offline): case offsetof(struct sched_ext_ops, init): case offsetof(struct sched_ext_ops, exit): break; @@ -4462,6 +4597,8 @@ static s32 init_task_stub(struct task_struct *p, struct scx_init_task_args *args static void exit_task_stub(struct task_struct *p, struct scx_exit_task_args *args) {} static void enable_stub(struct task_struct *p) {} static void disable_stub(struct task_struct *p) {} +static void cpu_online_stub(s32 cpu) {} +static void cpu_offline_stub(s32 cpu) {} static s32 init_stub(void) { return -EINVAL; } static void exit_stub(struct scx_exit_info *info) {} @@ -4484,6 +4621,8 @@ static struct sched_ext_ops __bpf_ops_sched_ext_ops = { .exit_task = exit_task_stub, .enable = enable_stub, .disable = disable_stub, + .cpu_online = cpu_online_stub, + .cpu_offline = cpu_offline_stub, .init = init_stub, .exit = exit_stub, }; @@ -4724,6 +4863,9 @@ void __init init_sched_ext_class(void) BUG_ON(!zalloc_cpumask_var(&rq->scx.cpus_to_preempt, GFP_KERNEL)); BUG_ON(!zalloc_cpumask_var(&rq->scx.cpus_to_wait, GFP_KERNEL)); init_irq_work(&rq->scx.kick_cpus_irq_work, kick_cpus_irq_workfn); + + if (cpu_online(cpu)) + cpu_rq(cpu)->scx.flags |= SCX_RQ_ONLINE; } register_sysrq_key('S', &sysrq_sched_ext_reset_op); diff --git a/kernel/sched/ext.h b/kernel/sched/ext.h index 4ebd1c2478f1..037f9acdf443 100644 --- a/kernel/sched/ext.h +++ b/kernel/sched/ext.h @@ -40,6 +40,8 @@ int scx_fork(struct task_struct *p); void scx_post_fork(struct task_struct *p); void scx_cancel_fork(struct task_struct *p); bool scx_can_stop_tick(struct rq *rq); +void scx_rq_activate(struct rq *rq); +void scx_rq_deactivate(struct rq *rq); int scx_check_setscheduler(struct task_struct *p, int policy); bool task_should_scx(struct task_struct *p); void init_sched_ext_class(void); @@ -81,6 +83,8 @@ static inline int scx_fork(struct task_struct *p) { return 0; } static inline void scx_post_fork(struct task_struct *p) {} static inline void scx_cancel_fork(struct task_struct *p) {} static inline bool scx_can_stop_tick(struct rq *rq) { return true; } +static inline void scx_rq_activate(struct rq *rq) {} +static inline void scx_rq_deactivate(struct rq *rq) {} static inline int scx_check_setscheduler(struct task_struct *p, int policy) { return 0; } static inline bool task_on_scx(const struct task_struct *p) { return false; } static inline void init_sched_ext_class(void) {} diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 435d2b145cfb..213e94c0dc91 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -825,6 +825,12 @@ struct cfs_rq { #ifdef CONFIG_SCHED_CLASS_EXT /* scx_rq->flags, protected by the rq lock */ enum scx_rq_flags { + /* + * A hotplugged CPU starts scheduling before rq_online_scx(). Track + * ops.cpu_on/offline() state so that ops.enqueue/dispatch() are called + * only while the BPF scheduler considers the CPU to be online. + */ + SCX_RQ_ONLINE = 1 << 0, SCX_RQ_BALANCING = 1 << 1, SCX_RQ_CAN_STOP_TICK = 1 << 2, }; diff --git a/tools/sched_ext/include/scx/compat.h b/tools/sched_ext/include/scx/compat.h index c58024c980c8..cc56ff9aa252 100644 --- a/tools/sched_ext/include/scx/compat.h +++ b/tools/sched_ext/include/scx/compat.h @@ -8,6 +8,9 @@ #define __SCX_COMPAT_H #include <bpf/btf.h> +#include <fcntl.h> +#include <stdlib.h> +#include <unistd.h> struct btf *__COMPAT_vmlinux_btf __attribute__((weak)); @@ -106,6 +109,28 @@ static inline bool __COMPAT_struct_has_field(const char *type, const char *field #define SCX_OPS_SWITCH_PARTIAL \ __COMPAT_ENUM_OR_ZERO("scx_ops_flags", "SCX_OPS_SWITCH_PARTIAL") +static inline long scx_hotplug_seq(void) +{ + int fd; + char buf[32]; + ssize_t len; + long val; + + fd = open("/sys/kernel/sched_ext/hotplug_seq", O_RDONLY); + if (fd < 0) + return -ENOENT; + + len = read(fd, buf, sizeof(buf) - 1); + SCX_BUG_ON(len <= 0, "read failed (%ld)", len); + buf[len] = 0; + close(fd); + + val = strtoul(buf, NULL, 10); + SCX_BUG_ON(val < 0, "invalid num hotplug events: %lu", val); + + return val; +} + /* * struct sched_ext_ops can change over time. If compat.bpf.h::SCX_OPS_DEFINE() * is used to define ops and compat.h::SCX_OPS_LOAD/ATTACH() are used to load @@ -123,6 +148,7 @@ static inline bool __COMPAT_struct_has_field(const char *type, const char *field \ __skel = __scx_name##__open(); \ SCX_BUG_ON(!__skel, "Could not open " #__scx_name); \ + __skel->struct_ops.__ops_name->hotplug_seq = scx_hotplug_seq(); \ __skel; \ }) diff --git a/tools/sched_ext/include/scx/user_exit_info.h b/tools/sched_ext/include/scx/user_exit_info.h index c2ef85c645e1..891693ee604e 100644 --- a/tools/sched_ext/include/scx/user_exit_info.h +++ b/tools/sched_ext/include/scx/user_exit_info.h @@ -77,7 +77,35 @@ struct user_exit_info { if (__uei->msg[0] != '\0') \ fprintf(stderr, " (%s)", __uei->msg); \ fputs("\n", stderr); \ + __uei->exit_code; \ }) +/* + * We can't import vmlinux.h while compiling user C code. Let's duplicate + * scx_exit_code definition. + */ +enum scx_exit_code { + /* Reasons */ + SCX_ECODE_RSN_HOTPLUG = 1LLU << 32, + + /* Actions */ + SCX_ECODE_ACT_RESTART = 1LLU << 48, +}; + +enum uei_ecode_mask { + UEI_ECODE_USER_MASK = ((1LLU << 32) - 1), + UEI_ECODE_SYS_RSN_MASK = ((1LLU << 16) - 1) << 32, + UEI_ECODE_SYS_ACT_MASK = ((1LLU << 16) - 1) << 48, +}; + +/* + * These macro interpret the ecode returned from UEI_REPORT(). + */ +#define UEI_ECODE_USER(__ecode) ((__ecode) & UEI_ECODE_USER_MASK) +#define UEI_ECODE_SYS_RSN(__ecode) ((__ecode) & UEI_ECODE_SYS_RSN_MASK) +#define UEI_ECODE_SYS_ACT(__ecode) ((__ecode) & UEI_ECODE_SYS_ACT_MASK) + +#define UEI_ECODE_RESTART(__ecode) (UEI_ECODE_SYS_ACT((__ecode)) == SCX_ECODE_ACT_RESTART) + #endif /* __bpf__ */ #endif /* __USER_EXIT_INFO_H */ diff --git a/tools/sched_ext/scx_central.c b/tools/sched_ext/scx_central.c index fb3f50886552..21deea320bd7 100644 --- a/tools/sched_ext/scx_central.c +++ b/tools/sched_ext/scx_central.c @@ -46,14 +46,14 @@ int main(int argc, char **argv) { struct scx_central *skel; struct bpf_link *link; - __u64 seq = 0; + __u64 seq = 0, ecode; __s32 opt; cpu_set_t *cpuset; libbpf_set_print(libbpf_print_fn); signal(SIGINT, sigint_handler); signal(SIGTERM, sigint_handler); - +restart: skel = SCX_OPS_OPEN(central_ops, scx_central); skel->rodata->central_cpu = 0; @@ -126,7 +126,10 @@ int main(int argc, char **argv) } bpf_link__destroy(link); - UEI_REPORT(skel, uei); + ecode = UEI_REPORT(skel, uei); scx_central__destroy(skel); + + if (UEI_ECODE_RESTART(ecode)) + goto restart; return 0; } diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c index 4a87377558c8..619078355bf5 100644 --- a/tools/sched_ext/scx_qmap.bpf.c +++ b/tools/sched_ext/scx_qmap.bpf.c @@ -358,8 +358,63 @@ void BPF_STRUCT_OPS(qmap_dump_task, struct scx_dump_ctx *dctx, struct task_struc taskc->force_local); } +/* + * Print out the online and possible CPU map using bpf_printk() as a + * demonstration of using the cpumask kfuncs and ops.cpu_on/offline(). + */ +static void print_cpus(void) +{ + const struct cpumask *possible, *online; + s32 cpu; + char buf[128] = "", *p; + int idx; + + possible = scx_bpf_get_possible_cpumask(); + online = scx_bpf_get_online_cpumask(); + + idx = 0; + bpf_for(cpu, 0, scx_bpf_nr_cpu_ids()) { + if (!(p = MEMBER_VPTR(buf, [idx++]))) + break; + if (bpf_cpumask_test_cpu(cpu, online)) + *p++ = 'O'; + else if (bpf_cpumask_test_cpu(cpu, possible)) + *p++ = 'X'; + else + *p++ = ' '; + + if ((cpu & 7) == 7) { + if (!(p = MEMBER_VPTR(buf, [idx++]))) + break; + *p++ = '|'; + } + } + buf[sizeof(buf) - 1] = '\0'; + + scx_bpf_put_cpumask(online); + scx_bpf_put_cpumask(possible); + + bpf_printk("CPUS: |%s", buf); +} + +void BPF_STRUCT_OPS(qmap_cpu_online, s32 cpu) +{ + bpf_printk("CPU %d coming online", cpu); + /* @cpu is already online at this point */ + print_cpus(); +} + +void BPF_STRUCT_OPS(qmap_cpu_offline, s32 cpu) +{ + bpf_printk("CPU %d going offline", cpu); + /* @cpu is still online at this point */ + print_cpus(); +} + s32 BPF_STRUCT_OPS_SLEEPABLE(qmap_init) { + print_cpus(); + return scx_bpf_create_dsq(SHARED_DSQ, -1); } @@ -378,6 +433,8 @@ SCX_OPS_DEFINE(qmap_ops, .dump = (void *)qmap_dump, .dump_cpu = (void *)qmap_dump_cpu, .dump_task = (void *)qmap_dump_task, + .cpu_online = (void *)qmap_cpu_online, + .cpu_offline = (void *)qmap_cpu_offline, .init = (void *)qmap_init, .exit = (void *)qmap_exit, .timeout_ms = 5000U, diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c index 2a97421afe9a..920fb54f9c77 100644 --- a/tools/sched_ext/scx_qmap.c +++ b/tools/sched_ext/scx_qmap.c @@ -122,5 +122,9 @@ int main(int argc, char **argv) bpf_link__destroy(link); UEI_REPORT(skel, uei); scx_qmap__destroy(skel); + /* + * scx_qmap implements ops.cpu_on/offline() and doesn't need to restart + * on CPU hotplug events. + */ return 0; } diff --git a/tools/sched_ext/scx_simple.c b/tools/sched_ext/scx_simple.c index 7f500d1d56ac..bead482e1383 100644 --- a/tools/sched_ext/scx_simple.c +++ b/tools/sched_ext/scx_simple.c @@ -62,11 +62,12 @@ int main(int argc, char **argv) struct scx_simple *skel; struct bpf_link *link; __u32 opt; + __u64 ecode; libbpf_set_print(libbpf_print_fn); signal(SIGINT, sigint_handler); signal(SIGTERM, sigint_handler); - +restart: skel = SCX_OPS_OPEN(simple_ops, scx_simple); while ((opt = getopt(argc, argv, "vh")) != -1) { @@ -93,7 +94,10 @@ int main(int argc, char **argv) } bpf_link__destroy(link); - UEI_REPORT(skel, uei); + ecode = UEI_REPORT(skel, uei); scx_simple__destroy(skel); + + if (UEI_ECODE_RESTART(ecode)) + goto restart; return 0; } -- 2.34.1