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-rw-r--r--tools/testing/selftests/sched_ext/Makefile1
-rw-r--r--tools/testing/selftests/sched_ext/dequeue.bpf.c389
-rw-r--r--tools/testing/selftests/sched_ext/dequeue.c274
3 files changed, 664 insertions, 0 deletions
diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile
index 2c601a7eaff5..2815a875bde2 100644
--- a/tools/testing/selftests/sched_ext/Makefile
+++ b/tools/testing/selftests/sched_ext/Makefile
@@ -161,6 +161,7 @@ all_test_bpfprogs := $(foreach prog,$(wildcard *.bpf.c),$(INCLUDE_DIR)/$(patsubs
auto-test-targets := \
create_dsq \
+ dequeue \
enq_last_no_enq_fails \
ddsp_bogus_dsq_fail \
ddsp_vtimelocal_fail \
diff --git a/tools/testing/selftests/sched_ext/dequeue.bpf.c b/tools/testing/selftests/sched_ext/dequeue.bpf.c
new file mode 100644
index 000000000000..597b88563d7d
--- /dev/null
+++ b/tools/testing/selftests/sched_ext/dequeue.bpf.c
@@ -0,0 +1,389 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * A scheduler that validates ops.dequeue() is called correctly:
+ * - Tasks dispatched to terminal DSQs (local, global) bypass the BPF
+ * scheduler entirely: no ops.dequeue() should be called
+ * - Tasks dispatched to user DSQs from ops.enqueue() enter BPF custody:
+ * ops.dequeue() must be called when they leave custody
+ * - Every ops.enqueue() dispatch to non-terminal DSQs is followed by
+ * exactly one ops.dequeue() (validate 1:1 pairing and state machine)
+ *
+ * Copyright (c) 2026 NVIDIA Corporation.
+ */
+
+#include <scx/common.bpf.h>
+
+#define SHARED_DSQ 0
+
+/*
+ * BPF internal queue.
+ *
+ * Tasks are stored here and consumed from ops.dispatch(), validating that
+ * tasks on BPF internal structures still get ops.dequeue() when they
+ * leave.
+ */
+struct {
+ __uint(type, BPF_MAP_TYPE_QUEUE);
+ __uint(max_entries, 32768);
+ __type(value, s32);
+} global_queue SEC(".maps");
+
+char _license[] SEC("license") = "GPL";
+
+UEI_DEFINE(uei);
+
+/*
+ * Counters to track the lifecycle of tasks:
+ * - enqueue_cnt: Number of times ops.enqueue() was called
+ * - dequeue_cnt: Number of times ops.dequeue() was called (any type)
+ * - dispatch_dequeue_cnt: Number of regular dispatch dequeues (no flag)
+ * - change_dequeue_cnt: Number of property change dequeues
+ * - bpf_queue_full: Number of times the BPF internal queue was full
+ */
+u64 enqueue_cnt, dequeue_cnt, dispatch_dequeue_cnt, change_dequeue_cnt, bpf_queue_full;
+
+/*
+ * Test scenarios:
+ * 0) Dispatch to local DSQ from ops.select_cpu() (terminal DSQ, bypasses BPF
+ * scheduler, no dequeue callbacks)
+ * 1) Dispatch to global DSQ from ops.select_cpu() (terminal DSQ, bypasses BPF
+ * scheduler, no dequeue callbacks)
+ * 2) Dispatch to shared user DSQ from ops.select_cpu() (enters BPF scheduler,
+ * dequeue callbacks expected)
+ * 3) Dispatch to local DSQ from ops.enqueue() (terminal DSQ, bypasses BPF
+ * scheduler, no dequeue callbacks)
+ * 4) Dispatch to global DSQ from ops.enqueue() (terminal DSQ, bypasses BPF
+ * scheduler, no dequeue callbacks)
+ * 5) Dispatch to shared user DSQ from ops.enqueue() (enters BPF scheduler,
+ * dequeue callbacks expected)
+ * 6) BPF internal queue from ops.enqueue(): store task PIDs in ops.enqueue(),
+ * consume in ops.dispatch() and dispatch to local DSQ (validates dequeue
+ * for tasks stored in internal BPF data structures)
+ */
+u32 test_scenario;
+
+/*
+ * Per-task state to track lifecycle and validate workflow semantics.
+ * State transitions:
+ * NONE -> ENQUEUED (on enqueue)
+ * NONE -> DISPATCHED (on direct dispatch to terminal DSQ)
+ * ENQUEUED -> DISPATCHED (on dispatch dequeue)
+ * DISPATCHED -> NONE (on property change dequeue or re-enqueue)
+ * ENQUEUED -> NONE (on property change dequeue before dispatch)
+ */
+enum task_state {
+ TASK_NONE = 0,
+ TASK_ENQUEUED,
+ TASK_DISPATCHED,
+};
+
+struct task_ctx {
+ enum task_state state; /* Current state in the workflow */
+ u64 enqueue_seq; /* Sequence number for debugging */
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
+ __uint(map_flags, BPF_F_NO_PREALLOC);
+ __type(key, int);
+ __type(value, struct task_ctx);
+} task_ctx_stor SEC(".maps");
+
+static struct task_ctx *try_lookup_task_ctx(struct task_struct *p)
+{
+ return bpf_task_storage_get(&task_ctx_stor, p, 0, 0);
+}
+
+s32 BPF_STRUCT_OPS(dequeue_select_cpu, struct task_struct *p,
+ s32 prev_cpu, u64 wake_flags)
+{
+ struct task_ctx *tctx;
+
+ tctx = try_lookup_task_ctx(p);
+ if (!tctx)
+ return prev_cpu;
+
+ switch (test_scenario) {
+ case 0:
+ /*
+ * Direct dispatch to the local DSQ.
+ *
+ * Task bypasses BPF scheduler entirely: no enqueue
+ * tracking, no ops.dequeue() callbacks.
+ */
+ scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL, SCX_SLICE_DFL, 0);
+ tctx->state = TASK_DISPATCHED;
+ break;
+ case 1:
+ /*
+ * Direct dispatch to the global DSQ.
+ *
+ * Task bypasses BPF scheduler entirely: no enqueue
+ * tracking, no ops.dequeue() callbacks.
+ */
+ scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, 0);
+ tctx->state = TASK_DISPATCHED;
+ break;
+ case 2:
+ /*
+ * Dispatch to a shared user DSQ.
+ *
+ * Task enters BPF scheduler management: track
+ * enqueue/dequeue lifecycle and validate state
+ * transitions.
+ */
+ if (tctx->state == TASK_ENQUEUED)
+ scx_bpf_error("%d (%s): enqueue while in ENQUEUED state seq=%llu",
+ p->pid, p->comm, tctx->enqueue_seq);
+
+ scx_bpf_dsq_insert(p, SHARED_DSQ, SCX_SLICE_DFL, 0);
+
+ __sync_fetch_and_add(&enqueue_cnt, 1);
+
+ tctx->state = TASK_ENQUEUED;
+ tctx->enqueue_seq++;
+ break;
+ }
+
+ return prev_cpu;
+}
+
+void BPF_STRUCT_OPS(dequeue_enqueue, struct task_struct *p, u64 enq_flags)
+{
+ struct task_ctx *tctx;
+ s32 pid = p->pid;
+
+ tctx = try_lookup_task_ctx(p);
+ if (!tctx)
+ return;
+
+ switch (test_scenario) {
+ case 3:
+ /*
+ * Direct dispatch to the local DSQ.
+ *
+ * Task bypasses BPF scheduler entirely: no enqueue
+ * tracking, no ops.dequeue() callbacks.
+ */
+ scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL, SCX_SLICE_DFL, enq_flags);
+ tctx->state = TASK_DISPATCHED;
+ break;
+ case 4:
+ /*
+ * Direct dispatch to the global DSQ.
+ *
+ * Task bypasses BPF scheduler entirely: no enqueue
+ * tracking, no ops.dequeue() callbacks.
+ */
+ scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
+ tctx->state = TASK_DISPATCHED;
+ break;
+ case 5:
+ /*
+ * Dispatch to shared user DSQ.
+ *
+ * Task enters BPF scheduler management: track
+ * enqueue/dequeue lifecycle and validate state
+ * transitions.
+ */
+ if (tctx->state == TASK_ENQUEUED)
+ scx_bpf_error("%d (%s): enqueue while in ENQUEUED state seq=%llu",
+ p->pid, p->comm, tctx->enqueue_seq);
+
+ scx_bpf_dsq_insert(p, SHARED_DSQ, SCX_SLICE_DFL, enq_flags);
+
+ __sync_fetch_and_add(&enqueue_cnt, 1);
+
+ tctx->state = TASK_ENQUEUED;
+ tctx->enqueue_seq++;
+ break;
+ case 6:
+ /*
+ * Store task in BPF internal queue.
+ *
+ * Task enters BPF scheduler management: track
+ * enqueue/dequeue lifecycle and validate state
+ * transitions.
+ */
+ if (tctx->state == TASK_ENQUEUED)
+ scx_bpf_error("%d (%s): enqueue while in ENQUEUED state seq=%llu",
+ p->pid, p->comm, tctx->enqueue_seq);
+
+ if (bpf_map_push_elem(&global_queue, &pid, 0)) {
+ scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
+ __sync_fetch_and_add(&bpf_queue_full, 1);
+
+ tctx->state = TASK_DISPATCHED;
+ } else {
+ __sync_fetch_and_add(&enqueue_cnt, 1);
+
+ tctx->state = TASK_ENQUEUED;
+ tctx->enqueue_seq++;
+ }
+ break;
+ default:
+ /* For all other scenarios, dispatch to the global DSQ */
+ scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
+ tctx->state = TASK_DISPATCHED;
+ break;
+ }
+
+ scx_bpf_kick_cpu(scx_bpf_task_cpu(p), SCX_KICK_IDLE);
+}
+
+void BPF_STRUCT_OPS(dequeue_dequeue, struct task_struct *p, u64 deq_flags)
+{
+ struct task_ctx *tctx;
+
+ __sync_fetch_and_add(&dequeue_cnt, 1);
+
+ tctx = try_lookup_task_ctx(p);
+ if (!tctx)
+ return;
+
+ /*
+ * For scenarios 0, 1, 3, and 4 (terminal DSQs: local and global),
+ * ops.dequeue() should never be called because tasks bypass the
+ * BPF scheduler entirely. If we get here, it's a kernel bug.
+ */
+ if (test_scenario == 0 || test_scenario == 3) {
+ scx_bpf_error("%d (%s): dequeue called for local DSQ scenario",
+ p->pid, p->comm);
+ return;
+ }
+
+ if (test_scenario == 1 || test_scenario == 4) {
+ scx_bpf_error("%d (%s): dequeue called for global DSQ scenario",
+ p->pid, p->comm);
+ return;
+ }
+
+ if (deq_flags & SCX_DEQ_SCHED_CHANGE) {
+ /*
+ * Property change interrupting the workflow. Valid from
+ * both ENQUEUED and DISPATCHED states. Transitions task
+ * back to NONE state.
+ */
+ __sync_fetch_and_add(&change_dequeue_cnt, 1);
+
+ /* Validate state transition */
+ if (tctx->state != TASK_ENQUEUED && tctx->state != TASK_DISPATCHED)
+ scx_bpf_error("%d (%s): invalid property change dequeue state=%d seq=%llu",
+ p->pid, p->comm, tctx->state, tctx->enqueue_seq);
+
+ /*
+ * Transition back to NONE: task outside scheduler control.
+ *
+ * Scenario 6: dispatch() checks tctx->state after popping a
+ * PID, if the task is in state NONE, it was dequeued by
+ * property change and must not be dispatched (this
+ * prevents "target CPU not allowed").
+ */
+ tctx->state = TASK_NONE;
+ } else {
+ /*
+ * Regular dispatch dequeue: kernel is moving the task from
+ * BPF custody to a terminal DSQ. Normally we come from
+ * ENQUEUED state. We can also see TASK_NONE if the task
+ * was dequeued by property change (SCX_DEQ_SCHED_CHANGE)
+ * while it was already on a DSQ (dispatched but not yet
+ * consumed); in that case we just leave state as NONE.
+ */
+ __sync_fetch_and_add(&dispatch_dequeue_cnt, 1);
+
+ /*
+ * Must be ENQUEUED (normal path) or NONE (already dequeued
+ * by property change while on a DSQ).
+ */
+ if (tctx->state != TASK_ENQUEUED && tctx->state != TASK_NONE)
+ scx_bpf_error("%d (%s): dispatch dequeue from state %d seq=%llu",
+ p->pid, p->comm, tctx->state, tctx->enqueue_seq);
+
+ if (tctx->state == TASK_ENQUEUED)
+ tctx->state = TASK_DISPATCHED;
+
+ /* NONE: leave as-is, task was already property-change dequeued */
+ }
+}
+
+void BPF_STRUCT_OPS(dequeue_dispatch, s32 cpu, struct task_struct *prev)
+{
+ if (test_scenario == 6) {
+ struct task_ctx *tctx;
+ struct task_struct *p;
+ s32 pid;
+
+ if (bpf_map_pop_elem(&global_queue, &pid))
+ return;
+
+ p = bpf_task_from_pid(pid);
+ if (!p)
+ return;
+
+ /*
+ * If the task was dequeued by property change
+ * (ops.dequeue() set tctx->state = TASK_NONE), skip
+ * dispatch.
+ */
+ tctx = try_lookup_task_ctx(p);
+ if (!tctx || tctx->state == TASK_NONE) {
+ bpf_task_release(p);
+ return;
+ }
+
+ /*
+ * Dispatch to this CPU's local DSQ if allowed, otherwise
+ * fallback to the global DSQ.
+ */
+ if (bpf_cpumask_test_cpu(cpu, p->cpus_ptr))
+ scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL_ON | cpu, SCX_SLICE_DFL, 0);
+ else
+ scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, 0);
+
+ bpf_task_release(p);
+ } else {
+ scx_bpf_dsq_move_to_local(SHARED_DSQ);
+ }
+}
+
+s32 BPF_STRUCT_OPS(dequeue_init_task, struct task_struct *p,
+ struct scx_init_task_args *args)
+{
+ struct task_ctx *tctx;
+
+ tctx = bpf_task_storage_get(&task_ctx_stor, p, 0,
+ BPF_LOCAL_STORAGE_GET_F_CREATE);
+ if (!tctx)
+ return -ENOMEM;
+
+ return 0;
+}
+
+s32 BPF_STRUCT_OPS_SLEEPABLE(dequeue_init)
+{
+ s32 ret;
+
+ ret = scx_bpf_create_dsq(SHARED_DSQ, -1);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+void BPF_STRUCT_OPS(dequeue_exit, struct scx_exit_info *ei)
+{
+ UEI_RECORD(uei, ei);
+}
+
+SEC(".struct_ops.link")
+struct sched_ext_ops dequeue_ops = {
+ .select_cpu = (void *)dequeue_select_cpu,
+ .enqueue = (void *)dequeue_enqueue,
+ .dequeue = (void *)dequeue_dequeue,
+ .dispatch = (void *)dequeue_dispatch,
+ .init_task = (void *)dequeue_init_task,
+ .init = (void *)dequeue_init,
+ .exit = (void *)dequeue_exit,
+ .flags = SCX_OPS_ENQ_LAST,
+ .name = "dequeue_test",
+};
diff --git a/tools/testing/selftests/sched_ext/dequeue.c b/tools/testing/selftests/sched_ext/dequeue.c
new file mode 100644
index 000000000000..4e93262703ca
--- /dev/null
+++ b/tools/testing/selftests/sched_ext/dequeue.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 NVIDIA Corporation.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <time.h>
+#include <bpf/bpf.h>
+#include <scx/common.h>
+#include <sys/wait.h>
+#include <sched.h>
+#include <pthread.h>
+#include "scx_test.h"
+#include "dequeue.bpf.skel.h"
+
+#define NUM_WORKERS 8
+#define AFFINITY_HAMMER_MS 500
+
+/*
+ * Worker function that creates enqueue/dequeue events via CPU work and
+ * sleep.
+ */
+static void worker_fn(int id)
+{
+ int i;
+ volatile int sum = 0;
+
+ for (i = 0; i < 1000; i++) {
+ volatile int j;
+
+ /* Do some work to trigger scheduling events */
+ for (j = 0; j < 10000; j++)
+ sum += j;
+
+ /* Sleep to trigger dequeue */
+ usleep(1000 + (id * 100));
+ }
+
+ exit(0);
+}
+
+/*
+ * This thread changes workers' affinity from outside so that some changes
+ * hit tasks while they are still in the scheduler's queue and trigger
+ * property-change dequeues.
+ */
+static void *affinity_hammer_fn(void *arg)
+{
+ pid_t *pids = arg;
+ cpu_set_t cpuset;
+ int i = 0, n = NUM_WORKERS;
+ struct timespec start, now;
+
+ clock_gettime(CLOCK_MONOTONIC, &start);
+ while (1) {
+ int w = i % n;
+ int cpu = (i / n) % 4;
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu, &cpuset);
+ sched_setaffinity(pids[w], sizeof(cpuset), &cpuset);
+ i++;
+
+ /* Check elapsed time every 256 iterations to limit gettime cost */
+ if ((i & 255) == 0) {
+ long long elapsed_ms;
+
+ clock_gettime(CLOCK_MONOTONIC, &now);
+ elapsed_ms = (now.tv_sec - start.tv_sec) * 1000LL +
+ (now.tv_nsec - start.tv_nsec) / 1000000;
+ if (elapsed_ms >= AFFINITY_HAMMER_MS)
+ break;
+ }
+ }
+ return NULL;
+}
+
+static enum scx_test_status run_scenario(struct dequeue *skel, u32 scenario,
+ const char *scenario_name)
+{
+ struct bpf_link *link;
+ pid_t pids[NUM_WORKERS];
+ pthread_t hammer;
+
+ int i, status;
+ u64 enq_start, deq_start,
+ dispatch_deq_start, change_deq_start, bpf_queue_full_start;
+ u64 enq_delta, deq_delta,
+ dispatch_deq_delta, change_deq_delta, bpf_queue_full_delta;
+
+ /* Set the test scenario */
+ skel->bss->test_scenario = scenario;
+
+ /* Record starting counts */
+ enq_start = skel->bss->enqueue_cnt;
+ deq_start = skel->bss->dequeue_cnt;
+ dispatch_deq_start = skel->bss->dispatch_dequeue_cnt;
+ change_deq_start = skel->bss->change_dequeue_cnt;
+ bpf_queue_full_start = skel->bss->bpf_queue_full;
+
+ link = bpf_map__attach_struct_ops(skel->maps.dequeue_ops);
+ SCX_FAIL_IF(!link, "Failed to attach struct_ops for scenario %s", scenario_name);
+
+ /* Fork worker processes to generate enqueue/dequeue events */
+ for (i = 0; i < NUM_WORKERS; i++) {
+ pids[i] = fork();
+ SCX_FAIL_IF(pids[i] < 0, "Failed to fork worker %d", i);
+
+ if (pids[i] == 0) {
+ worker_fn(i);
+ /* Should not reach here */
+ exit(1);
+ }
+ }
+
+ /*
+ * Run an "affinity hammer" so that some property changes hit tasks
+ * while they are still in BPF custody (e.g., in user DSQ or BPF
+ * queue), triggering SCX_DEQ_SCHED_CHANGE dequeues.
+ */
+ SCX_FAIL_IF(pthread_create(&hammer, NULL, affinity_hammer_fn, pids) != 0,
+ "Failed to create affinity hammer thread");
+ pthread_join(hammer, NULL);
+
+ /* Wait for all workers to complete */
+ for (i = 0; i < NUM_WORKERS; i++) {
+ SCX_FAIL_IF(waitpid(pids[i], &status, 0) != pids[i],
+ "Failed to wait for worker %d", i);
+ SCX_FAIL_IF(status != 0, "Worker %d exited with status %d", i, status);
+ }
+
+ bpf_link__destroy(link);
+
+ SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_UNREG));
+
+ /* Calculate deltas */
+ enq_delta = skel->bss->enqueue_cnt - enq_start;
+ deq_delta = skel->bss->dequeue_cnt - deq_start;
+ dispatch_deq_delta = skel->bss->dispatch_dequeue_cnt - dispatch_deq_start;
+ change_deq_delta = skel->bss->change_dequeue_cnt - change_deq_start;
+ bpf_queue_full_delta = skel->bss->bpf_queue_full - bpf_queue_full_start;
+
+ printf("%s:\n", scenario_name);
+ printf(" enqueues: %lu\n", (unsigned long)enq_delta);
+ printf(" dequeues: %lu (dispatch: %lu, property_change: %lu)\n",
+ (unsigned long)deq_delta,
+ (unsigned long)dispatch_deq_delta,
+ (unsigned long)change_deq_delta);
+ printf(" BPF queue full: %lu\n", (unsigned long)bpf_queue_full_delta);
+
+ /*
+ * Validate enqueue/dequeue lifecycle tracking.
+ *
+ * For scenarios 0, 1, 3, 4 (local and global DSQs from
+ * ops.select_cpu() and ops.enqueue()), both enqueues and dequeues
+ * should be 0 because tasks bypass the BPF scheduler entirely:
+ * tasks never enter BPF scheduler's custody.
+ *
+ * For scenarios 2, 5, 6 (user DSQ or BPF internal queue) we expect
+ * both enqueues and dequeues.
+ *
+ * The BPF code does strict state machine validation with
+ * scx_bpf_error() to ensure the workflow semantics are correct.
+ *
+ * If we reach this point without errors, the semantics are
+ * validated correctly.
+ */
+ if (scenario == 0 || scenario == 1 ||
+ scenario == 3 || scenario == 4) {
+ /* Tasks bypass BPF scheduler completely */
+ SCX_EQ(enq_delta, 0);
+ SCX_EQ(deq_delta, 0);
+ SCX_EQ(dispatch_deq_delta, 0);
+ SCX_EQ(change_deq_delta, 0);
+ } else {
+ /*
+ * User DSQ from ops.enqueue() or ops.select_cpu(): tasks
+ * enter BPF scheduler's custody.
+ *
+ * Also validate 1:1 enqueue/dequeue pairing.
+ */
+ SCX_GT(enq_delta, 0);
+ SCX_GT(deq_delta, 0);
+ SCX_EQ(enq_delta, deq_delta);
+ }
+
+ return SCX_TEST_PASS;
+}
+
+static enum scx_test_status setup(void **ctx)
+{
+ struct dequeue *skel;
+
+ skel = dequeue__open();
+ SCX_FAIL_IF(!skel, "Failed to open skel");
+ SCX_ENUM_INIT(skel);
+ SCX_FAIL_IF(dequeue__load(skel), "Failed to load skel");
+
+ *ctx = skel;
+
+ return SCX_TEST_PASS;
+}
+
+static enum scx_test_status run(void *ctx)
+{
+ struct dequeue *skel = ctx;
+ enum scx_test_status status;
+
+ status = run_scenario(skel, 0, "Scenario 0: Local DSQ from ops.select_cpu()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 1, "Scenario 1: Global DSQ from ops.select_cpu()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 2, "Scenario 2: User DSQ from ops.select_cpu()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 3, "Scenario 3: Local DSQ from ops.enqueue()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 4, "Scenario 4: Global DSQ from ops.enqueue()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 5, "Scenario 5: User DSQ from ops.enqueue()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ status = run_scenario(skel, 6, "Scenario 6: BPF queue from ops.enqueue()");
+ if (status != SCX_TEST_PASS)
+ return status;
+
+ printf("\n=== Summary ===\n");
+ printf("Total enqueues: %lu\n", (unsigned long)skel->bss->enqueue_cnt);
+ printf("Total dequeues: %lu\n", (unsigned long)skel->bss->dequeue_cnt);
+ printf(" Dispatch dequeues: %lu (no flag, normal workflow)\n",
+ (unsigned long)skel->bss->dispatch_dequeue_cnt);
+ printf(" Property change dequeues: %lu (SCX_DEQ_SCHED_CHANGE flag)\n",
+ (unsigned long)skel->bss->change_dequeue_cnt);
+ printf(" BPF queue full: %lu\n",
+ (unsigned long)skel->bss->bpf_queue_full);
+ printf("\nAll scenarios passed - no state machine violations detected\n");
+ printf("-> Validated: Local DSQ dispatch bypasses BPF scheduler\n");
+ printf("-> Validated: Global DSQ dispatch bypasses BPF scheduler\n");
+ printf("-> Validated: User DSQ dispatch triggers ops.dequeue() callbacks\n");
+ printf("-> Validated: Dispatch dequeues have no flags (normal workflow)\n");
+ printf("-> Validated: Property change dequeues have SCX_DEQ_SCHED_CHANGE flag\n");
+ printf("-> Validated: No duplicate enqueues or invalid state transitions\n");
+
+ return SCX_TEST_PASS;
+}
+
+static void cleanup(void *ctx)
+{
+ struct dequeue *skel = ctx;
+
+ dequeue__destroy(skel);
+}
+
+struct scx_test dequeue_test = {
+ .name = "dequeue",
+ .description = "Verify ops.dequeue() semantics",
+ .setup = setup,
+ .run = run,
+ .cleanup = cleanup,
+};
+
+REGISTER_SCX_TEST(&dequeue_test)
generated by cgit v1.2.3 (git 2.39.0) at 2026-05-13 10:29:05 +0300