Changes in kernel/generic/src/sysinfo/stats.c [07d4271:fe7bcf1] in mainline

File:

• kernel/generic/src/sysinfo/stats.c (modified) (11 diffs)

kernel/generic/src/sysinfo/stats.c

@@ -119 +119 @@
         size_t i;
         for (i = 0; i < config.cpu_count; i++) {
+                irq_spinlock_lock(&cpus[i].lock, true);
+
                 stats_cpus[i].id = cpus[i].id;
                 stats_cpus[i].active = cpus[i].active;
                 stats_cpus[i].frequency_mhz = cpus[i].frequency_mhz;
-
-                stats_cpus[i].busy_cycles = atomic_time_read(&cpus[i].busy_cycles);
-                stats_cpus[i].idle_cycles = atomic_time_read(&cpus[i].idle_cycles);
+                stats_cpus[i].busy_cycles = cpus[i].busy_cycles;
+                stats_cpus[i].idle_cycles = cpus[i].idle_cycles;
+
+                irq_spinlock_unlock(&cpus[i].lock, true);
         }
 
@@ -221 +224 @@
         stats_task->virtmem = get_task_virtmem(task->as);
         stats_task->resmem = get_task_resmem(task->as);
-        stats_task->threads = atomic_load(&task->lifecount);
+        stats_task->threads = atomic_load(&task->refcount);
         task_get_accounting(task, &(stats_task->ucycles),
             &(stats_task->kcycles));
@@ -299 +302 @@
 {
         assert(interrupts_disabled());
+        assert(irq_spinlock_locked(&thread->lock));
 
         stats_thread->thread_id = thread->tid;
         stats_thread->task_id = thread->task->taskid;
-        stats_thread->state = atomic_get_unordered(&thread->state);
-        stats_thread->priority = atomic_get_unordered(&thread->priority);
-        stats_thread->ucycles = atomic_time_read(&thread->ucycles);
-        stats_thread->kcycles = atomic_time_read(&thread->kcycles);
-
-        cpu_t *cpu = atomic_get_unordered(&thread->cpu);
-
-        if (cpu != NULL) {
+        stats_thread->state = thread->state;
+        stats_thread->priority = thread->priority;
+        stats_thread->ucycles = thread->ucycles;
+        stats_thread->kcycles = thread->kcycles;
+
+        if (thread->cpu != NULL) {
                 stats_thread->on_cpu = true;
-                stats_thread->cpu = cpu->id;
+                stats_thread->cpu = thread->cpu->id;
         } else
                 stats_thread->on_cpu = false;
@@ -330 +332 @@
     bool dry_run, void *data)
 {
-        /* Messing with threads structures */
+        /* Messing with threads structures, avoid deadlock */
         irq_spinlock_lock(&threads_lock, true);
 
@@ -362 +364 @@
         thread_t *thread = thread_first();
         while (thread != NULL) {
+                /* Interrupts are already disabled */
+                irq_spinlock_lock(&thread->lock, false);
+
                 /* Record the statistics and increment the index */
                 produce_stats_thread(thread, &stats_threads[i]);
                 i++;
+
+                irq_spinlock_unlock(&thread->lock, false);
 
                 thread = thread_next(thread);
@@ -511 +518 @@
 {
         /* Initially no return value */
-        sysinfo_return_t ret = {
-                .tag = SYSINFO_VAL_UNDEFINED,
-        };
+        sysinfo_return_t ret;
+        ret.tag = SYSINFO_VAL_UNDEFINED;
 
         /* Parse the task ID */
@@ -520 +526 @@
                 return ret;
 
+        /* Messing with task structures, avoid deadlock */
+        irq_spinlock_lock(&tasks_lock, true);
+
         task_t *task = task_find_by_id(task_id);
-        if (!task)
+        if (task == NULL) {
+                /* No task with this ID */
+                irq_spinlock_unlock(&tasks_lock, true);
                 return ret;
+        }
 
         if (dry_run) {
@@ -528 +540 @@
                 ret.data.data = NULL;
                 ret.data.size = sizeof(stats_task_t);
+
+                irq_spinlock_unlock(&tasks_lock, true);
         } else {
                 /* Allocate stats_task_t structure */
-                stats_task_t *stats_task = malloc(sizeof(stats_task_t));
-
-                if (stats_task != NULL) {
-                        /* Correct return value */
-                        ret.tag = SYSINFO_VAL_FUNCTION_DATA;
-                        ret.data.data = stats_task;
-                        ret.data.size = sizeof(stats_task_t);
-
-                        irq_spinlock_lock(&task->lock, true);
-                        produce_stats_task(task, stats_task);
-                        irq_spinlock_unlock(&task->lock, true);
+                stats_task_t *stats_task =
+                    (stats_task_t *) malloc(sizeof(stats_task_t));
+                if (stats_task == NULL) {
+                        irq_spinlock_unlock(&tasks_lock, true);
+                        return ret;
                 }
-        }
-
-        task_release(task);
+
+                /* Correct return value */
+                ret.tag = SYSINFO_VAL_FUNCTION_DATA;
+                ret.data.data = (void *) stats_task;
+                ret.data.size = sizeof(stats_task_t);
+
+                /* Hand-over-hand locking */
+                irq_spinlock_exchange(&tasks_lock, &task->lock);
+
+                produce_stats_task(task, stats_task);
+
+                irq_spinlock_unlock(&task->lock, true);
+        }
+
         return ret;
 }
@@ -578 +597 @@
                 return ret;
 
-        /* Messing with threads structures */
+        /* Messing with threads structures, avoid deadlock */
         irq_spinlock_lock(&threads_lock, true);
 
@@ -608 +627 @@
                 ret.data.size = sizeof(stats_thread_t);
 
+                /* Hand-over-hand locking */
+                irq_spinlock_exchange(&threads_lock, &thread->lock);
+
                 produce_stats_thread(thread, stats_thread);
 
-                irq_spinlock_unlock(&threads_lock, true);
+                irq_spinlock_unlock(&thread->lock, true);
         }
 
@@ -825 +847 @@
 void kload(void *arg)
 {
+        thread_detach(THREAD);
+
         while (true) {
                 size_t ready = atomic_load(&nrdy);