From 9d35fa170b23d0aa9e7724629d55f8c2c6e38e99 Mon Sep 17 00:00:00 2001 From: Peter Jung Date: Thu, 18 Dec 2025 16:42:35 +0100 Subject: [PATCH 10/11] sched-ext Signed-off-by: Peter Jung --- include/linux/sched/ext.h | 1 + kernel/sched/ext.c | 69 ++++- tools/sched_ext/include/scx/common.bpf.h | 1 + tools/sched_ext/include/scx/compat.bpf.h | 18 ++ tools/testing/selftests/sched_ext/Makefile | 1 + .../selftests/sched_ext/peek_dsq.bpf.c | 251 ++++++++++++++++++ tools/testing/selftests/sched_ext/peek_dsq.c | 224 ++++++++++++++++ 7 files changed, 561 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/sched_ext/peek_dsq.bpf.c create mode 100644 tools/testing/selftests/sched_ext/peek_dsq.c diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h index d82b7a9b0658..81478d4ae782 100644 --- a/include/linux/sched/ext.h +++ b/include/linux/sched/ext.h @@ -58,6 +58,7 @@ enum scx_dsq_id_flags { */ struct scx_dispatch_q { raw_spinlock_t lock; + struct task_struct __rcu *first_task; /* lockless peek at head */ struct list_head list; /* tasks in dispatch order */ struct rb_root priq; /* used to order by p->scx.dsq_vtime */ u32 nr; diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 979484dab2d3..9acc660c350c 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -965,8 +965,11 @@ static void dispatch_enqueue(struct scx_sched *sch, struct scx_dispatch_q *dsq, container_of(rbp, struct task_struct, scx.dsq_priq); list_add(&p->scx.dsq_list.node, &prev->scx.dsq_list.node); + /* first task unchanged - no update needed */ } else { list_add(&p->scx.dsq_list.node, &dsq->list); + /* not builtin and new task is at head - use fastpath */ + rcu_assign_pointer(dsq->first_task, p); } } else { /* a FIFO DSQ shouldn't be using PRIQ enqueuing */ @@ -974,10 +977,19 @@ static void dispatch_enqueue(struct scx_sched *sch, struct scx_dispatch_q *dsq, scx_error(sch, "DSQ ID 0x%016llx already had PRIQ-enqueued tasks", dsq->id); - if (enq_flags & (SCX_ENQ_HEAD | SCX_ENQ_PREEMPT)) + if (enq_flags & (SCX_ENQ_HEAD | SCX_ENQ_PREEMPT)) { list_add(&p->scx.dsq_list.node, &dsq->list); - else + /* new task inserted at head - use fastpath */ + if (!(dsq->id & SCX_DSQ_FLAG_BUILTIN)) + rcu_assign_pointer(dsq->first_task, p); + } else { + bool was_empty; + + was_empty = list_empty(&dsq->list); list_add_tail(&p->scx.dsq_list.node, &dsq->list); + if (was_empty && !(dsq->id & SCX_DSQ_FLAG_BUILTIN)) + rcu_assign_pointer(dsq->first_task, p); + } } /* seq records the order tasks are queued, used by BPF DSQ iterator */ @@ -1034,6 +1046,13 @@ static void task_unlink_from_dsq(struct task_struct *p, list_del_init(&p->scx.dsq_list.node); dsq_mod_nr(dsq, -1); + + if (!(dsq->id & SCX_DSQ_FLAG_BUILTIN) && dsq->first_task == p) { + struct task_struct *first_task; + + first_task = nldsq_next_task(dsq, NULL, false); + rcu_assign_pointer(dsq->first_task, first_task); + } } static void dispatch_dequeue(struct rq *rq, struct task_struct *p) @@ -4516,7 +4535,7 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops) return ERR_PTR(ret); } -static void check_hotplug_seq(struct scx_sched *sch, +static int check_hotplug_seq(struct scx_sched *sch, const struct sched_ext_ops *ops) { unsigned long long global_hotplug_seq; @@ -4533,8 +4552,11 @@ static void check_hotplug_seq(struct scx_sched *sch, SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG, "expected hotplug seq %llu did not match actual %llu", ops->hotplug_seq, global_hotplug_seq); + return -EBUSY; } } + + return 0; } static int validate_ops(struct scx_sched *sch, const struct sched_ext_ops *ops) @@ -4636,7 +4658,11 @@ static int scx_enable(struct sched_ext_ops *ops, struct bpf_link *link) if (((void (**)(void))ops)[i]) set_bit(i, sch->has_op); - check_hotplug_seq(sch, ops); + ret = check_hotplug_seq(sch, ops); + if (ret) { + cpus_read_unlock(); + goto err_disable; + } scx_idle_update_selcpu_topology(ops); cpus_read_unlock(); @@ -6183,6 +6209,40 @@ __bpf_kfunc void bpf_iter_scx_dsq_destroy(struct bpf_iter_scx_dsq *it) kit->dsq = NULL; } +/** + * scx_bpf_dsq_peek - Lockless peek at the first element. + * @dsq_id: DSQ to examine. + * + * Read the first element in the DSQ. This is semantically equivalent to using + * the DSQ iterator, but is lockfree. Of course, like any lockless operation, + * this provides only a point-in-time snapshot, and the contents may change + * by the time any subsequent locking operation reads the queue. + * + * Returns the pointer, or NULL indicates an empty queue OR internal error. + */ +__bpf_kfunc struct task_struct *scx_bpf_dsq_peek(u64 dsq_id) +{ + struct scx_sched *sch; + struct scx_dispatch_q *dsq; + + sch = rcu_dereference(scx_root); + if (unlikely(!sch)) + return NULL; + + if (unlikely(dsq_id & SCX_DSQ_FLAG_BUILTIN)) { + scx_error(sch, "peek disallowed on builtin DSQ 0x%llx", dsq_id); + return NULL; + } + + dsq = find_user_dsq(sch, dsq_id); + if (unlikely(!dsq)) { + scx_error(sch, "peek on non-existent DSQ 0x%llx", dsq_id); + return NULL; + } + + return rcu_dereference(dsq->first_task); +} + __bpf_kfunc_end_defs(); static s32 __bstr_format(struct scx_sched *sch, u64 *data_buf, char *line_buf, @@ -6740,6 +6800,7 @@ BTF_KFUNCS_START(scx_kfunc_ids_any) BTF_ID_FLAGS(func, scx_bpf_kick_cpu) BTF_ID_FLAGS(func, scx_bpf_dsq_nr_queued) BTF_ID_FLAGS(func, scx_bpf_destroy_dsq) +BTF_ID_FLAGS(func, scx_bpf_dsq_peek, KF_RCU_PROTECTED | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_scx_dsq_new, KF_ITER_NEW | KF_RCU_PROTECTED) BTF_ID_FLAGS(func, bpf_iter_scx_dsq_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_scx_dsq_destroy, KF_ITER_DESTROY) diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index 06e2551033cb..fbf3e7f9526c 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -75,6 +75,7 @@ u32 scx_bpf_reenqueue_local(void) __ksym; void scx_bpf_kick_cpu(s32 cpu, u64 flags) __ksym; s32 scx_bpf_dsq_nr_queued(u64 dsq_id) __ksym; void scx_bpf_destroy_dsq(u64 dsq_id) __ksym; +struct task_struct *scx_bpf_dsq_peek(u64 dsq_id) __ksym __weak; int bpf_iter_scx_dsq_new(struct bpf_iter_scx_dsq *it, u64 dsq_id, u64 flags) __ksym __weak; struct task_struct *bpf_iter_scx_dsq_next(struct bpf_iter_scx_dsq *it) __ksym __weak; void bpf_iter_scx_dsq_destroy(struct bpf_iter_scx_dsq *it) __ksym __weak; diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h index dd9144624dc9..467a987880e1 100644 --- a/tools/sched_ext/include/scx/compat.bpf.h +++ b/tools/sched_ext/include/scx/compat.bpf.h @@ -130,6 +130,24 @@ int bpf_cpumask_populate(struct cpumask *dst, void *src, size_t src__sz) __ksym false; \ }) +/* + * v6.19: Introduce lockless peek API for user DSQs. + * + * Preserve the following macro until v6.21. + */ +static inline struct task_struct *__COMPAT_scx_bpf_dsq_peek(u64 dsq_id) +{ + struct task_struct *p = NULL; + struct bpf_iter_scx_dsq it; + + if (bpf_ksym_exists(scx_bpf_dsq_peek)) + return scx_bpf_dsq_peek(dsq_id); + if (!bpf_iter_scx_dsq_new(&it, dsq_id, 0)) + p = bpf_iter_scx_dsq_next(&it); + bpf_iter_scx_dsq_destroy(&it); + return p; +} + /** * __COMPAT_is_enq_cpu_selected - Test if SCX_ENQ_CPU_SELECTED is on * in a compatible way. We will preserve this __COMPAT helper until v6.16. diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile index 9d9d6b4c38b0..5fe45f9c5f8f 100644 --- a/tools/testing/selftests/sched_ext/Makefile +++ b/tools/testing/selftests/sched_ext/Makefile @@ -174,6 +174,7 @@ auto-test-targets := \ minimal \ numa \ allowed_cpus \ + peek_dsq \ prog_run \ reload_loop \ select_cpu_dfl \ diff --git a/tools/testing/selftests/sched_ext/peek_dsq.bpf.c b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c new file mode 100644 index 000000000000..a3faf5bb49d6 --- /dev/null +++ b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * A BPF program for testing DSQ operations and peek in particular. + * + * Copyright (c) 2025 Meta Platforms, Inc. and affiliates. + * Copyright (c) 2025 Ryan Newton + */ + +#include +#include + +char _license[] SEC("license") = "GPL"; + +UEI_DEFINE(uei); /* Error handling */ + +#define MAX_SAMPLES 100 +#define MAX_CPUS 512 +#define DSQ_POOL_SIZE 8 +int max_samples = MAX_SAMPLES; +int max_cpus = MAX_CPUS; +int dsq_pool_size = DSQ_POOL_SIZE; + +/* Global variables to store test results */ +int dsq_peek_result1 = -1; +long dsq_inserted_pid = -1; +int insert_test_cpu = -1; /* Set to the cpu that performs the test */ +long dsq_peek_result2 = -1; +long dsq_peek_result2_pid = -1; +long dsq_peek_result2_expected = -1; +int test_dsq_id = 1234; /* Use a simple ID like create_dsq example */ +int real_dsq_id = 1235; /* DSQ for normal operation */ +int enqueue_count = -1; +int dispatch_count = -1; +bool debug_ksym_exists; + +/* DSQ pool for stress testing */ +int dsq_pool_base_id = 2000; +int phase1_complete = -1; +long total_peek_attempts = -1; +long successful_peeks = -1; + +/* BPF map for sharing peek results with userspace */ +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, MAX_SAMPLES); + __type(key, u32); + __type(value, long); +} peek_results SEC(".maps"); + +static int get_random_dsq_id(void) +{ + u64 time = bpf_ktime_get_ns(); + + return dsq_pool_base_id + (time % DSQ_POOL_SIZE); +} + +static void record_peek_result(long pid) +{ + u32 slot_key; + long *slot_pid_ptr; + int ix; + + if (pid <= 0) + return; + + /* Find an empty slot or one with the same PID */ + bpf_for(ix, 0, 10) { + slot_key = (pid + ix) % MAX_SAMPLES; + slot_pid_ptr = bpf_map_lookup_elem(&peek_results, &slot_key); + if (!slot_pid_ptr) + continue; + + if (*slot_pid_ptr == -1 || *slot_pid_ptr == pid) { + *slot_pid_ptr = pid; + break; + } + } +} + +/* Scan all DSQs in the pool and try to move a task to local */ +static int scan_dsq_pool(void) +{ + struct task_struct *task; + int moved = 0; + int i; + + bpf_for(i, 0, DSQ_POOL_SIZE) { + int dsq_id = dsq_pool_base_id + i; + + total_peek_attempts++; + + task = __COMPAT_scx_bpf_dsq_peek(dsq_id); + if (task) { + successful_peeks++; + record_peek_result(task->pid); + + /* Try to move this task to local */ + if (!moved && scx_bpf_dsq_move_to_local(dsq_id) == 0) { + moved = 1; + break; + } + } + } + return moved; +} + +/* Struct_ops scheduler for testing DSQ peek operations */ +void BPF_STRUCT_OPS(peek_dsq_enqueue, struct task_struct *p, u64 enq_flags) +{ + struct task_struct *peek_result; + int last_insert_test_cpu, cpu; + + enqueue_count++; + cpu = bpf_get_smp_processor_id(); + last_insert_test_cpu = __sync_val_compare_and_swap(&insert_test_cpu, -1, cpu); + + /* Phase 1: Simple insert-then-peek test (only on first task) */ + if (last_insert_test_cpu == -1) { + bpf_printk("peek_dsq_enqueue beginning phase 1 peek test on cpu %d", cpu); + + /* Test 1: Peek empty DSQ - should return NULL */ + peek_result = __COMPAT_scx_bpf_dsq_peek(test_dsq_id); + dsq_peek_result1 = (long)peek_result; /* Should be 0 (NULL) */ + + /* Test 2: Insert task into test DSQ for testing in dispatch callback */ + dsq_inserted_pid = p->pid; + scx_bpf_dsq_insert(p, test_dsq_id, 0, enq_flags); + dsq_peek_result2_expected = (long)p; /* Expected the task we just inserted */ + } else if (!phase1_complete) { + /* Still in phase 1, use real DSQ */ + scx_bpf_dsq_insert(p, real_dsq_id, 0, enq_flags); + } else { + /* Phase 2: Random DSQ insertion for stress testing */ + int random_dsq_id = get_random_dsq_id(); + + scx_bpf_dsq_insert(p, random_dsq_id, 0, enq_flags); + } +} + +void BPF_STRUCT_OPS(peek_dsq_dispatch, s32 cpu, struct task_struct *prev) +{ + dispatch_count++; + + /* Phase 1: Complete the simple peek test if we inserted a task but + * haven't tested peek yet + */ + if (insert_test_cpu == cpu && dsq_peek_result2 == -1) { + struct task_struct *peek_result; + + bpf_printk("peek_dsq_dispatch completing phase 1 peek test on cpu %d", cpu); + + /* Test 3: Peek DSQ after insert - should return the task we inserted */ + peek_result = __COMPAT_scx_bpf_dsq_peek(test_dsq_id); + /* Store the PID of the peeked task for comparison */ + dsq_peek_result2 = (long)peek_result; + dsq_peek_result2_pid = peek_result ? peek_result->pid : -1; + + /* Now consume the task since we've peeked at it */ + scx_bpf_dsq_move_to_local(test_dsq_id); + + /* Mark phase 1 as complete */ + phase1_complete = 1; + bpf_printk("Phase 1 complete, starting phase 2 stress testing"); + } else if (!phase1_complete) { + /* Still in phase 1, use real DSQ */ + scx_bpf_dsq_move_to_local(real_dsq_id); + } else { + /* Phase 2: Scan all DSQs in the pool and try to move a task */ + if (!scan_dsq_pool()) { + /* No tasks found in DSQ pool, fall back to real DSQ */ + scx_bpf_dsq_move_to_local(real_dsq_id); + } + } +} + +s32 BPF_STRUCT_OPS_SLEEPABLE(peek_dsq_init) +{ + s32 err; + int i; + + /* Always set debug values so we can see which version we're using */ + debug_ksym_exists = bpf_ksym_exists(scx_bpf_dsq_peek) ? 1 : 0; + + /* Initialize state first */ + insert_test_cpu = -1; + enqueue_count = 0; + dispatch_count = 0; + phase1_complete = 0; + total_peek_attempts = 0; + successful_peeks = 0; + + /* Create the test and real DSQs */ + err = scx_bpf_create_dsq(test_dsq_id, -1); + if (err) { + scx_bpf_error("Failed to create DSQ %d: %d", test_dsq_id, err); + return err; + } + err = scx_bpf_create_dsq(real_dsq_id, -1); + if (err) { + scx_bpf_error("Failed to create DSQ %d: %d", test_dsq_id, err); + return err; + } + + /* Create the DSQ pool for stress testing */ + bpf_for(i, 0, DSQ_POOL_SIZE) { + int dsq_id = dsq_pool_base_id + i; + + err = scx_bpf_create_dsq(dsq_id, -1); + if (err) { + scx_bpf_error("Failed to create DSQ pool entry %d: %d", dsq_id, err); + return err; + } + } + + /* Initialize the peek results map */ + bpf_for(i, 0, MAX_SAMPLES) { + u32 key = i; + long pid = -1; + + bpf_map_update_elem(&peek_results, &key, &pid, BPF_ANY); + } + + return 0; +} + +void BPF_STRUCT_OPS(peek_dsq_exit, struct scx_exit_info *ei) +{ + int i; + + /* Destroy the primary DSQs */ + scx_bpf_destroy_dsq(test_dsq_id); + scx_bpf_destroy_dsq(real_dsq_id); + + /* Destroy the DSQ pool */ + bpf_for(i, 0, DSQ_POOL_SIZE) { + int dsq_id = dsq_pool_base_id + i; + + scx_bpf_destroy_dsq(dsq_id); + } + + UEI_RECORD(uei, ei); +} + +SEC(".struct_ops.link") +struct sched_ext_ops peek_dsq_ops = { + .enqueue = (void *)peek_dsq_enqueue, + .dispatch = (void *)peek_dsq_dispatch, + .init = (void *)peek_dsq_init, + .exit = (void *)peek_dsq_exit, + .name = "peek_dsq", +}; diff --git a/tools/testing/selftests/sched_ext/peek_dsq.c b/tools/testing/selftests/sched_ext/peek_dsq.c new file mode 100644 index 000000000000..a717384a3224 --- /dev/null +++ b/tools/testing/selftests/sched_ext/peek_dsq.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test for DSQ operations including create, destroy, and peek operations. + * + * Copyright (c) 2025 Meta Platforms, Inc. and affiliates. + * Copyright (c) 2025 Ryan Newton + */ +#include +#include +#include +#include +#include +#include +#include +#include "peek_dsq.bpf.skel.h" +#include "scx_test.h" + +#define NUM_WORKERS 4 + +static bool workload_running = true; +static pthread_t workload_threads[NUM_WORKERS]; + +/** + * Background workload thread that sleeps and wakes rapidly to exercise + * the scheduler's enqueue operations and ensure DSQ operations get tested. + */ +static void *workload_thread_fn(void *arg) +{ + while (workload_running) { + /* Sleep for a very short time to trigger scheduler activity */ + usleep(1000); /* 1ms sleep */ + /* Yield to ensure we go through the scheduler */ + sched_yield(); + } + return NULL; +} + +static enum scx_test_status setup(void **ctx) +{ + struct peek_dsq *skel; + + skel = peek_dsq__open(); + SCX_FAIL_IF(!skel, "Failed to open"); + SCX_ENUM_INIT(skel); + SCX_FAIL_IF(peek_dsq__load(skel), "Failed to load skel"); + + *ctx = skel; + + return SCX_TEST_PASS; +} + +static int print_observed_pids(struct bpf_map *map, int max_samples, const char *dsq_name) +{ + long count = 0; + + printf("Observed %s DSQ peek pids:\n", dsq_name); + for (int i = 0; i < max_samples; i++) { + long pid; + int err; + + err = bpf_map_lookup_elem(bpf_map__fd(map), &i, &pid); + if (err == 0) { + if (pid == 0) { + printf(" Sample %d: NULL peek\n", i); + } else if (pid > 0) { + printf(" Sample %d: pid %ld\n", i, pid); + count++; + } + } else { + printf(" Sample %d: error reading pid (err=%d)\n", i, err); + } + } + printf("Observed ~%ld pids in the %s DSQ(s)\n", count, dsq_name); + return count; +} + +static enum scx_test_status run(void *ctx) +{ + struct peek_dsq *skel = ctx; + bool failed = false; + int seconds = 3; + int err; + + /* Enable the scheduler to test DSQ operations */ + printf("Enabling scheduler to test DSQ insert operations...\n"); + + struct bpf_link *link = + bpf_map__attach_struct_ops(skel->maps.peek_dsq_ops); + + if (!link) { + SCX_ERR("Failed to attach struct_ops"); + return SCX_TEST_FAIL; + } + + printf("Starting %d background workload threads...\n", NUM_WORKERS); + workload_running = true; + for (int i = 0; i < NUM_WORKERS; i++) { + err = pthread_create(&workload_threads[i], NULL, workload_thread_fn, NULL); + if (err) { + SCX_ERR("Failed to create workload thread %d: %s", i, strerror(err)); + /* Stop already created threads */ + workload_running = false; + for (int j = 0; j < i; j++) + pthread_join(workload_threads[j], NULL); + bpf_link__destroy(link); + return SCX_TEST_FAIL; + } + } + + printf("Waiting for enqueue events.\n"); + sleep(seconds); + while (skel->data->enqueue_count <= 0) { + printf("."); + fflush(stdout); + sleep(1); + seconds++; + if (seconds >= 30) { + printf("\n\u2717 Timeout waiting for enqueue events\n"); + /* Stop workload threads and cleanup */ + workload_running = false; + for (int i = 0; i < NUM_WORKERS; i++) + pthread_join(workload_threads[i], NULL); + bpf_link__destroy(link); + return SCX_TEST_FAIL; + } + } + + workload_running = false; + for (int i = 0; i < NUM_WORKERS; i++) { + err = pthread_join(workload_threads[i], NULL); + if (err) { + SCX_ERR("Failed to join workload thread %d: %s", i, strerror(err)); + bpf_link__destroy(link); + return SCX_TEST_FAIL; + } + } + printf("Background workload threads stopped.\n"); + + SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE)); + + /* Detach the scheduler */ + bpf_link__destroy(link); + + printf("Enqueue/dispatch count over %d seconds: %d / %d\n", seconds, + skel->data->enqueue_count, skel->data->dispatch_count); + printf("Debug: ksym_exists=%d\n", + skel->bss->debug_ksym_exists); + + /* Check DSQ insert result */ + printf("DSQ insert test done on cpu: %d\n", skel->data->insert_test_cpu); + if (skel->data->insert_test_cpu != -1) + printf("\u2713 DSQ insert succeeded !\n"); + else { + printf("\u2717 DSQ insert failed or not attempted\n"); + failed = true; + } + + /* Check DSQ peek results */ + printf(" DSQ peek result 1 (before insert): %d\n", + skel->data->dsq_peek_result1); + if (skel->data->dsq_peek_result1 == 0) + printf("\u2713 DSQ peek verification success: peek returned NULL!\n"); + else { + printf("\u2717 DSQ peek verification failed\n"); + failed = true; + } + + printf(" DSQ peek result 2 (after insert): %ld\n", + skel->data->dsq_peek_result2); + printf(" DSQ peek result 2, expected: %ld\n", + skel->data->dsq_peek_result2_expected); + if (skel->data->dsq_peek_result2 == + skel->data->dsq_peek_result2_expected) + printf("\u2713 DSQ peek verification success: peek returned the inserted task!\n"); + else { + printf("\u2717 DSQ peek verification failed\n"); + failed = true; + } + + printf(" Inserted test task -> pid: %ld\n", skel->data->dsq_inserted_pid); + printf(" DSQ peek result 2 -> pid: %ld\n", skel->data->dsq_peek_result2_pid); + + int pid_count; + + pid_count = print_observed_pids(skel->maps.peek_results, + skel->data->max_samples, "DSQ pool"); + printf("Total non-null peek observations: %ld out of %ld\n", + skel->data->successful_peeks, skel->data->total_peek_attempts); + + if (skel->bss->debug_ksym_exists && pid_count == 0) { + printf("\u2717 DSQ pool test failed: no successful peeks in native mode\n"); + failed = true; + } + if (skel->bss->debug_ksym_exists && pid_count > 0) + printf("\u2713 DSQ pool test success: observed successful peeks in native mode\n"); + + if (failed) + return SCX_TEST_FAIL; + else + return SCX_TEST_PASS; +} + +static void cleanup(void *ctx) +{ + struct peek_dsq *skel = ctx; + + if (workload_running) { + workload_running = false; + for (int i = 0; i < NUM_WORKERS; i++) + pthread_join(workload_threads[i], NULL); + } + + peek_dsq__destroy(skel); +} + +struct scx_test peek_dsq = { + .name = "peek_dsq", + .description = + "Test DSQ create/destroy operations and future peek functionality", + .setup = setup, + .run = run, + .cleanup = cleanup, +}; +REGISTER_SCX_TEST(&peek_dsq) -- 2.52.0