/* * litmus/sched_cedf.c * * Implementation of the C-EDF scheduling algorithm. * * This implementation is based on G-EDF: * - CPUs are clustered around L2 or L3 caches. * - Clusters topology is automatically detected (this is arch dependent * and is working only on x86 at the moment --- and only with modern * cpus that exports cpuid4 information) * - The plugins _does not_ attempt to put tasks in the right cluster i.e. * the programmer needs to be aware of the topology to place tasks * in the desired cluster * - default clustering is around L2 cache (cache index = 2) * supported clusters are: L1 (private cache: pedf), L2, L3, ALL (all * online_cpus are placed in a single cluster). * * For details on functions, take a look at sched_gsn_edf.c * * Currently, we do not support changes in the number of online cpus. * If the num_online_cpus() dynamically changes, the plugin is broken. * * This version uses the simple approach and serializes all scheduling * decisions by the use of a queue lock. This is probably not the * best way to do it, but it should suffice for now. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_LITMUS_LOCKING #include #endif #ifdef CONFIG_LITMUS_NESTED_LOCKING #include #include #include #endif #ifdef CONFIG_SCHED_CPU_AFFINITY #include #endif #ifdef CONFIG_REALTIME_AUX_TASKS #include #endif /* to configure the cluster size */ #include #ifdef CONFIG_SCHED_CPU_AFFINITY #include #endif #ifdef CONFIG_LITMUS_SOFTIRQD #include #endif #ifdef CONFIG_LITMUS_PAI_SOFTIRQD #include #endif #ifdef CONFIG_LITMUS_NVIDIA #include #endif #if defined(CONFIG_LITMUS_AFFINITY_LOCKING) && defined(CONFIG_LITMUS_NVIDIA) #include #endif /* Reference configuration variable. Determines which cache level is used to * group CPUs into clusters. GLOBAL_CLUSTER, which is the default, means that * all CPUs form a single cluster (just like GSN-EDF). */ static enum cache_level cluster_config = GLOBAL_CLUSTER; struct clusterdomain; /* cpu_entry_t - maintain the linked and scheduled state * * A cpu also contains a pointer to the cedf_domain_t cluster * that owns it (struct clusterdomain*) */ typedef struct { int cpu; struct clusterdomain* cluster; /* owning cluster */ struct task_struct* linked; /* only RT tasks */ struct task_struct* scheduled; /* only RT tasks */ atomic_t will_schedule; /* prevent unneeded IPIs */ struct binheap_node hn; } cpu_entry_t; /* one cpu_entry_t per CPU */ DEFINE_PER_CPU(cpu_entry_t, cedf_cpu_entries); #define set_will_schedule() \ (atomic_set(&__get_cpu_var(cedf_cpu_entries).will_schedule, 1)) #define clear_will_schedule() \ (atomic_set(&__get_cpu_var(cedf_cpu_entries).will_schedule, 0)) #define test_will_schedule(cpu) \ (atomic_read(&per_cpu(cedf_cpu_entries, cpu).will_schedule)) /* * In C-EDF there is a cedf domain _per_ cluster * The number of clusters is dynamically determined accordingly to the * total cpu number and the cluster size */ typedef struct clusterdomain { /* rt_domain for this cluster */ rt_domain_t domain; /* cpus in this cluster */ cpu_entry_t* *cpus; /* map of this cluster cpus */ cpumask_var_t cpu_map; /* the cpus queue themselves according to priority in here */ struct binheap cpu_heap; /* lock for this cluster */ #define cluster_lock domain.ready_lock #ifdef CONFIG_LITMUS_PAI_SOFTIRQD struct tasklet_head pending_tasklets; #endif #ifdef CONFIG_LITMUS_DGL_SUPPORT raw_spinlock_t dgl_lock; #endif } cedf_domain_t; /* a cedf_domain per cluster; allocation is done at init/activation time */ cedf_domain_t *cedf; #define remote_cluster(cpu) ((cedf_domain_t *) per_cpu(cedf_cpu_entries, cpu).cluster) #define task_cpu_cluster(task) remote_cluster(get_partition(task)) /* total number of cluster */ static int num_clusters; /* we do not support cluster of different sizes */ static unsigned int cluster_size; static int clusters_allocated = 0; #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD) static int num_gpu_clusters; static unsigned int gpu_cluster_size; #endif #ifdef CONFIG_LITMUS_DGL_SUPPORT static raw_spinlock_t* cedf_get_dgl_spinlock(struct task_struct *t) { cedf_domain_t *cluster = task_cpu_cluster(t); return(&cluster->dgl_lock); } #endif /* Uncomment WANT_ALL_SCHED_EVENTS if you want to see all scheduling * decisions in the TRACE() log; uncomment VERBOSE_INIT for verbose * information during the initialization of the plugin (e.g., topology) #define WANT_ALL_SCHED_EVENTS */ #define VERBOSE_INIT static int cpu_lower_prio(struct binheap_node *_a, struct binheap_node *_b) { cpu_entry_t *a = binheap_entry(_a, cpu_entry_t, hn); cpu_entry_t *b = binheap_entry(_b, cpu_entry_t, hn); /* Note that a and b are inverted: we want the lowest-priority CPU at * the top of the heap. */ return edf_higher_prio(b->linked, a->linked); } /* update_cpu_position - Move the cpu entry to the correct place to maintain * order in the cpu queue. Caller must hold cedf lock. */ static void update_cpu_position(cpu_entry_t *entry) { cedf_domain_t *cluster = entry->cluster; if (likely(binheap_is_in_heap(&entry->hn))) { binheap_delete(&entry->hn, &cluster->cpu_heap); } binheap_add(&entry->hn, &cluster->cpu_heap, cpu_entry_t, hn); } /* caller must hold cedf lock */ static cpu_entry_t* lowest_prio_cpu(cedf_domain_t *cluster) { return binheap_top_entry(&cluster->cpu_heap, cpu_entry_t, hn); } static noinline void unlink(struct task_struct* t); /* link_task_to_cpu - Update the link of a CPU. * Handles the case where the to-be-linked task is already * scheduled on a different CPU. */ static noinline void link_task_to_cpu(struct task_struct* linked, cpu_entry_t *entry) { cpu_entry_t *sched; struct task_struct* tmp; int on_cpu; BUG_ON(linked && !is_realtime(linked)); /* Currently linked task is set to be unlinked. */ if (entry->linked) { entry->linked->rt_param.linked_on = NO_CPU; } /* Link new task to CPU. */ if (linked) { tsk_rt(linked)->completed = 0; /* handle task is already scheduled somewhere! */ on_cpu = linked->rt_param.scheduled_on; if (on_cpu != NO_CPU) { sched = &per_cpu(cedf_cpu_entries, on_cpu); BUG_ON(sched->linked == linked); /* If we are already scheduled on the CPU to which we * wanted to link, we don't need to do the swap -- * we just link ourselves to the CPU and depend on * the caller to get things right. */ if (entry != sched) { TRACE_TASK(linked, "already scheduled on %d, updating link.\n", sched->cpu); tmp = sched->linked; linked->rt_param.linked_on = sched->cpu; sched->linked = linked; update_cpu_position(sched); linked = tmp; } } if (linked) /* might be NULL due to swap */ linked->rt_param.linked_on = entry->cpu; } entry->linked = linked; #ifdef WANT_ALL_SCHED_EVENTS if (linked) TRACE_TASK(linked, "linked to %d.\n", entry->cpu); else TRACE("NULL linked to %d.\n", entry->cpu); #endif update_cpu_position(entry); } /* unlink - Make sure a task is not linked any longer to an entry * where it was linked before. Must hold cluster_lock. */ static noinline void unlink(struct task_struct* t) { if (t->rt_param.linked_on != NO_CPU) { /* unlink */ cpu_entry_t *entry = &per_cpu(cedf_cpu_entries, t->rt_param.linked_on); t->rt_param.linked_on = NO_CPU; link_task_to_cpu(NULL, entry); } else if (is_queued(t)) { /* This is an interesting situation: t is scheduled, * but was just recently unlinked. It cannot be * linked anywhere else (because then it would have * been relinked to this CPU), thus it must be in some * queue. We must remove it from the list in this * case. * * in C-EDF case is should be somewhere in the queue for * its domain, therefore and we can get the domain using * task_cpu_cluster */ remove(&(task_cpu_cluster(t))->domain, t); } } /* preempt - force a CPU to reschedule */ static void preempt(cpu_entry_t *entry) { preempt_if_preemptable(entry->scheduled, entry->cpu); } /* requeue - Put an unlinked task into gsn-edf domain. * Caller must hold cluster_lock. */ static noinline void requeue(struct task_struct* task) { cedf_domain_t *cluster = task_cpu_cluster(task); BUG_ON(!task); /* sanity check before insertion */ BUG_ON(is_queued(task)); if (is_released(task, litmus_clock())) #ifdef CONFIG_REALTIME_AUX_TASKS if (unlikely(tsk_rt(task)->is_aux_task && task->state != TASK_RUNNING && !tsk_rt(task)->aux_ready)) { /* aux_task probably transitioned to real-time while it was blocked */ TRACE_CUR("aux task %s/%d is not ready!\n", task->comm, task->pid); tsk_rt(task)->aux_ready = 1; /* allow this to only happen once per aux task */ } else #endif __add_ready(&cluster->domain, task); else { /* it has got to wait */ add_release(&cluster->domain, task); } } #ifdef CONFIG_SCHED_CPU_AFFINITY static cpu_entry_t* cedf_get_nearest_available_cpu( cedf_domain_t *cluster, cpu_entry_t *start) { cpu_entry_t *affinity; get_nearest_available_cpu(affinity, start, cedf_cpu_entries, #ifdef CONFIG_RELEASE_MASTER cluster->domain.release_master #else NO_CPU #endif ); /* make sure CPU is in our cluster */ if (affinity && cpu_isset(affinity->cpu, *cluster->cpu_map)) return(affinity); else return(NULL); } #endif /* check for any necessary preemptions */ static void check_for_preemptions(cedf_domain_t *cluster) { struct task_struct *task; cpu_entry_t *last; for(last = lowest_prio_cpu(cluster); edf_preemption_needed(&cluster->domain, last->linked); last = lowest_prio_cpu(cluster)) { /* preemption necessary */ task = __take_ready(&cluster->domain); TRACE("check_for_preemptions: attempting to link task %d to %d\n", task->pid, last->cpu); #ifdef CONFIG_SCHED_CPU_AFFINITY { cpu_entry_t *affinity = cedf_get_nearest_available_cpu(cluster, &per_cpu(cedf_cpu_entries, task_cpu(task))); if(affinity) last = affinity; else if(requeue_preempted_job(last->linked)) requeue(last->linked); } #else if (requeue_preempted_job(last->linked)) requeue(last->linked); #endif link_task_to_cpu(task, last); preempt(last); } } /* cedf_job_arrival: task is either resumed or released */ static noinline void cedf_job_arrival(struct task_struct* task) { cedf_domain_t *cluster = task_cpu_cluster(task); BUG_ON(!task); requeue(task); check_for_preemptions(cluster); } static void cedf_release_jobs(rt_domain_t* rt, struct bheap* tasks) { cedf_domain_t* cluster = container_of(rt, cedf_domain_t, domain); unsigned long flags; raw_spin_lock_irqsave(&cluster->cluster_lock, flags); __merge_ready(&cluster->domain, tasks); check_for_preemptions(cluster); raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); } /* caller holds cluster_lock */ static noinline void job_completion(struct task_struct *t, int forced) { BUG_ON(!t); sched_trace_task_completion(t, forced); TRACE_TASK(t, "job_completion() at %llu.\n", litmus_clock()); #ifdef CONFIG_LITMUS_LOCKING BUG_ON(!is_persistent(t) && tsk_rt(t)->inh_task); #endif /* set flags */ tsk_rt(t)->completed = 1; /* prepare for next period */ prepare_for_next_period(t); if (is_released(t, litmus_clock())) sched_trace_task_release(t); /* unlink */ unlink(t); /* requeue * But don't requeue a blocking task. */ if (is_running(t)) cedf_job_arrival(t); } /* cedf_tick - this function is called for every local timer * interrupt. * * checks whether the current task has expired and checks * whether we need to preempt it if it has not expired */ static void cedf_tick(struct task_struct* t) { if (is_realtime(t) && budget_exhausted(t)) { if (budget_signalled(t) && !sigbudget_sent(t)) { /* signal exhaustion */ send_sigbudget(t); } if (budget_enforced(t)) { if (!is_np(t)) { /* np tasks will be preempted when they become * preemptable again */ litmus_reschedule_local(); set_will_schedule(); TRACE("cedf_scheduler_tick: " "%d is preemptable " " => FORCE_RESCHED\n", t->pid); } else if (is_user_np(t)) { TRACE("cedf_scheduler_tick: " "%d is non-preemptable, " "preemption delayed.\n", t->pid); request_exit_np(t); } } } } #ifdef CONFIG_LITMUS_PAI_SOFTIRQD static void __do_lit_tasklet(struct tasklet_struct* tasklet, unsigned long flushed) { if (!atomic_read(&tasklet->count)) { if(tasklet->owner) { sched_trace_tasklet_begin(tasklet->owner); } if (!test_and_clear_bit(TASKLET_STATE_SCHED, &tasklet->state)) { BUG(); } TRACE("%s: Invoking tasklet with owner pid = %d (flushed = %d).\n", __FUNCTION__, (tasklet->owner) ? tasklet->owner->pid : 0, (tasklet->owner) ? 0 : 1); tasklet->func(tasklet->data); tasklet_unlock(tasklet); if(tasklet->owner) { sched_trace_tasklet_end(tasklet->owner, flushed); } } else { BUG(); } } static void do_lit_tasklets(cedf_domain_t* cluster, struct task_struct* sched_task) { int work_to_do = 1; struct tasklet_struct *tasklet = NULL; unsigned long flags; while(work_to_do) { TS_NV_SCHED_BOTISR_START; raw_spin_lock_irqsave(&cluster->cluster_lock, flags); if(cluster->pending_tasklets.head != NULL) { // remove tasklet at head. struct tasklet_struct *prev = NULL; tasklet = cluster->pending_tasklets.head; // find a tasklet with prio to execute; skip ones where // sched_task has a higher priority. // We use the '!edf' test instead of swaping function arguments since // both sched_task and owner could be NULL. In this case, we want to // still execute the tasklet. while(tasklet && !edf_higher_prio(tasklet->owner, sched_task)) { prev = tasklet; tasklet = tasklet->next; } if(tasklet) { // found something to execuite // remove the tasklet from the queue if(prev) { prev->next = tasklet->next; if(prev->next == NULL) { TRACE("%s: Tasklet for %d is the last element in tasklet queue.\n", __FUNCTION__, tasklet->owner->pid); cluster->pending_tasklets.tail = &(prev); } } else { cluster->pending_tasklets.head = tasklet->next; if(tasklet->next == NULL) { TRACE("%s: Tasklet for %d is the last element in tasklet queue.\n", __FUNCTION__, tasklet->owner->pid); cluster->pending_tasklets.tail = &(cluster->pending_tasklets.head); } } } else { TRACE("%s: No tasklets with eligible priority.\n", __FUNCTION__); } } else { TRACE("%s: Tasklet queue is empty.\n", __FUNCTION__); } raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); if(tasklet) { __do_lit_tasklet(tasklet, 0ul); tasklet = NULL; } else { work_to_do = 0; } TS_NV_SCHED_BOTISR_END; } } static void __add_pai_tasklet(struct tasklet_struct* tasklet, cedf_domain_t* cluster) { struct tasklet_struct* step; tasklet->next = NULL; // make sure there are no old values floating around step = cluster->pending_tasklets.head; if(step == NULL) { TRACE("%s: tasklet queue empty. inserting tasklet for %d at head.\n", __FUNCTION__, tasklet->owner->pid); // insert at tail. *(cluster->pending_tasklets.tail) = tasklet; cluster->pending_tasklets.tail = &(tasklet->next); } else if((*(cluster->pending_tasklets.tail) != NULL) && edf_higher_prio((*(cluster->pending_tasklets.tail))->owner, tasklet->owner)) { // insert at tail. TRACE("%s: tasklet belongs at end. inserting tasklet for %d at tail.\n", __FUNCTION__, tasklet->owner->pid); *(cluster->pending_tasklets.tail) = tasklet; cluster->pending_tasklets.tail = &(tasklet->next); } else { // insert the tasklet somewhere in the middle. TRACE("%s: tasklet belongs somewhere in the middle.\n", __FUNCTION__); while(step->next && edf_higher_prio(step->next->owner, tasklet->owner)) { step = step->next; } // insert tasklet right before step->next. TRACE("%s: inserting tasklet for %d between %d and %d.\n", __FUNCTION__, tasklet->owner->pid, (step->owner) ? step->owner->pid : -1, (step->next) ? ((step->next->owner) ? step->next->owner->pid : -1) : -1); tasklet->next = step->next; step->next = tasklet; // patch up the head if needed. if(cluster->pending_tasklets.head == step) { TRACE("%s: %d is the new tasklet queue head.\n", __FUNCTION__, tasklet->owner->pid); cluster->pending_tasklets.head = tasklet; } } } static void cedf_run_tasklets(struct task_struct* sched_task) { cedf_domain_t* cluster; preempt_disable(); cluster = (is_realtime(sched_task)) ? task_cpu_cluster(sched_task) : remote_cluster(smp_processor_id()); if(cluster && cluster->pending_tasklets.head != NULL) { TRACE("%s: There are tasklets to process.\n", __FUNCTION__); do_lit_tasklets(cluster, sched_task); } preempt_enable_no_resched(); } static int cedf_enqueue_pai_tasklet(struct tasklet_struct* tasklet) { #if 0 cedf_domain_t *cluster = NULL; cpu_entry_t *targetCPU = NULL; int thisCPU; int runLocal = 0; int runNow = 0; unsigned long flags; if(unlikely((tasklet->owner == NULL) || !is_realtime(tasklet->owner))) { TRACE("%s: No owner associated with this tasklet!\n", __FUNCTION__); return 0; } cluster = task_cpu_cluster(tasklet->owner); raw_spin_lock_irqsave(&cluster->cluster_lock, flags); thisCPU = smp_processor_id(); #ifdef CONFIG_SCHED_CPU_AFFINITY { cpu_entry_t* affinity = NULL; // use this CPU if it is in our cluster and isn't running any RT work. if(cpu_isset(thisCPU, *cluster->cpu_map) && (__get_cpu_var(cedf_cpu_entries).linked == NULL)) { affinity = &(__get_cpu_var(cedf_cpu_entries)); } else { // this CPU is busy or shouldn't run tasklet in this cluster. // look for available near by CPUs. // NOTE: Affinity towards owner and not this CPU. Is this right? affinity = cedf_get_nearest_available_cpu(cluster, &per_cpu(cedf_cpu_entries, task_cpu(tasklet->owner))); } targetCPU = affinity; } #endif if (targetCPU == NULL) { targetCPU = lowest_prio_cpu(cluster); } if (edf_higher_prio(tasklet->owner, targetCPU->linked)) { if (thisCPU == targetCPU->cpu) { TRACE("%s: Run tasklet locally (and now).\n", __FUNCTION__); runLocal = 1; runNow = 1; } else { TRACE("%s: Run tasklet remotely (and now).\n", __FUNCTION__); runLocal = 0; runNow = 1; } } else { runLocal = 0; runNow = 0; } if(!runLocal) { // enqueue the tasklet __add_pai_tasklet(tasklet, cluster); } raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); if (runLocal /*&& runNow */) { // runNow == 1 is implied TRACE("%s: Running tasklet on CPU where it was received.\n", __FUNCTION__); __do_lit_tasklet(tasklet, 0ul); } else if (runNow /*&& !runLocal */) { // runLocal == 0 is implied TRACE("%s: Triggering CPU %d to run tasklet.\n", __FUNCTION__, targetCPU->cpu); preempt(targetCPU); // need to be protected by cluster_lock? } else { TRACE("%s: Scheduling of tasklet was deferred.\n", __FUNCTION__); } #else TRACE("%s: Running tasklet on CPU where it was received.\n", __FUNCTION__); __do_lit_tasklet(tasklet, 0ul); #endif return(1); // success } static void cedf_change_prio_pai_tasklet(struct task_struct *old_prio, struct task_struct *new_prio) { struct tasklet_struct* step; unsigned long flags; cedf_domain_t *cluster; struct task_struct *probe; // identify the cluster by the assignment of these tasks. one should // be non-NULL. probe = (old_prio) ? old_prio : new_prio; if(probe) { cluster = task_cpu_cluster(probe); if(cluster->pending_tasklets.head != NULL) { raw_spin_lock_irqsave(&cluster->cluster_lock, flags); for(step = cluster->pending_tasklets.head; step != NULL; step = step->next) { if(step->owner == old_prio) { TRACE("%s: Found tasklet to change: %d\n", __FUNCTION__, step->owner->pid); step->owner = new_prio; } } raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); } } else { TRACE("%s: Both priorities were NULL\n"); } } #endif // PAI /* Getting schedule() right is a bit tricky. schedule() may not make any * assumptions on the state of the current task since it may be called for a * number of reasons. The reasons include a scheduler_tick() determined that it * was necessary, because sys_exit_np() was called, because some Linux * subsystem determined so, or even (in the worst case) because there is a bug * hidden somewhere. Thus, we must take extreme care to determine what the * current state is. * * The CPU could currently be scheduling a task (or not), be linked (or not). * * The following assertions for the scheduled task could hold: * * - !is_running(scheduled) // the job blocks * - scheduled->timeslice == 0 // the job completed (forcefully) * - is_completed() // the job completed (by syscall) * - linked != scheduled // we need to reschedule (for any reason) * - is_np(scheduled) // rescheduling must be delayed, * sys_exit_np must be requested * * Any of these can occur together. */ static struct task_struct* cedf_schedule(struct task_struct * prev) { cpu_entry_t* entry = &__get_cpu_var(cedf_cpu_entries); cedf_domain_t *cluster = entry->cluster; int out_of_time, signal_budget, sleep, preempt, np, exists, blocks; struct task_struct* next = NULL; #ifdef CONFIG_RELEASE_MASTER /* Bail out early if we are the release master. * The release master never schedules any real-time tasks. */ if (unlikely(cluster->domain.release_master == entry->cpu)) { sched_state_task_picked(); return NULL; } #endif raw_spin_lock(&cluster->cluster_lock); clear_will_schedule(); /* sanity checking */ BUG_ON(entry->scheduled && entry->scheduled != prev); BUG_ON(entry->scheduled && !is_realtime(prev)); BUG_ON(is_realtime(prev) && !entry->scheduled); /* (0) Determine state */ exists = entry->scheduled != NULL; blocks = exists && !is_running(entry->scheduled); out_of_time = exists && budget_enforced(entry->scheduled) && budget_exhausted(entry->scheduled); signal_budget = exists && budget_signalled(entry->scheduled) && budget_exhausted(entry->scheduled) && !sigbudget_sent(entry->scheduled); np = exists && is_np(entry->scheduled); sleep = exists && is_completed(entry->scheduled); preempt = entry->scheduled != entry->linked; #ifdef WANT_ALL_SCHED_EVENTS TRACE_TASK(prev, "invoked cedf_schedule.\n"); #endif if (exists) TRACE_TASK(prev, "blocks:%d out_of_time:%d np:%d sleep:%d preempt:%d " "state:%d sig:%d\n", blocks, out_of_time, np, sleep, preempt, prev->state, signal_pending(prev)); if (entry->linked && preempt) TRACE_TASK(prev, "will be preempted by %s/%d\n", entry->linked->comm, entry->linked->pid); #ifdef CONFIG_REALTIME_AUX_TASKS if (tsk_rt(prev)->is_aux_task && (prev->state == TASK_INTERRUPTIBLE) && !blocks) { TRACE_TASK(prev, "Deferring descheduling of aux task %s/%d.\n", prev->comm, prev->pid); next = prev; /* allow prev to continue. */ goto out_set_state; } #endif /* Send the signal that the budget has been exhausted */ if (signal_budget) send_sigbudget(entry->scheduled); /* If a task blocks we have no choice but to reschedule. */ if (blocks) unlink(entry->scheduled); #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_AFFINITY_LOCKING) if(exists && is_realtime(entry->scheduled) && tsk_rt(entry->scheduled)->held_gpus) { if(!blocks || tsk_rt(entry->scheduled)->suspend_gpu_tracker_on_block) { // don't track preemptions or locking protocol suspensions. TRACE_TASK(entry->scheduled, "stopping GPU tracker.\n"); stop_gpu_tracker(entry->scheduled); } else if(blocks && !tsk_rt(entry->scheduled)->suspend_gpu_tracker_on_block) { TRACE_TASK(entry->scheduled, "GPU tracker remains on during suspension.\n"); } } #endif /* Request a sys_exit_np() call if we would like to preempt but cannot. * We need to make sure to update the link structure anyway in case * that we are still linked. Multiple calls to request_exit_np() don't * hurt. */ if (np && (out_of_time || preempt || sleep)) { unlink(entry->scheduled); request_exit_np(entry->scheduled); } /* Any task that is preemptable and either exhausts its execution * budget or wants to sleep completes. We may have to reschedule after * this. Don't do a job completion if we block (can't have timers running * for blocked jobs). */ if (!np && (out_of_time || sleep) && !blocks) job_completion(entry->scheduled, !sleep); /* Link pending task if we became unlinked. */ if (!entry->linked) link_task_to_cpu(__take_ready(&cluster->domain), entry); /* The final scheduling decision. Do we need to switch for some reason? * If linked is different from scheduled, then select linked as next. */ if ((!np || blocks) && entry->linked != entry->scheduled) { /* Schedule a linked job? */ if (entry->linked) { entry->linked->rt_param.scheduled_on = entry->cpu; next = entry->linked; } if (entry->scheduled) { /* not gonna be scheduled soon */ entry->scheduled->rt_param.scheduled_on = NO_CPU; TRACE_TASK(entry->scheduled, "scheduled_on = NO_CPU\n"); } } else { /* Only override Linux scheduler if we have a real-time task * scheduled that needs to continue. */ if (exists) { next = prev; } } #ifdef CONFIG_REALTIME_AUX_TASKS out_set_state: #endif sched_state_task_picked(); raw_spin_unlock(&cluster->cluster_lock); #ifdef WANT_ALL_SCHED_EVENTS TRACE("cluster_lock released, next=0x%p\n", next); if (next) TRACE_TASK(next, "scheduled at %llu\n", litmus_clock()); else if (exists && !next) TRACE("becomes idle at %llu.\n", litmus_clock()); #endif return next; } /* _finish_switch - we just finished the switch away from prev */ static void cedf_finish_switch(struct task_struct *prev) { cpu_entry_t* entry = &__get_cpu_var(cedf_cpu_entries); entry->scheduled = is_realtime(current) ? current : NULL; #ifdef WANT_ALL_SCHED_EVENTS TRACE_TASK(prev, "switched away from\n"); #endif } /* Prepare a task for running in RT mode */ static void cedf_task_new(struct task_struct * t, int on_rq, int running) { unsigned long flags; cpu_entry_t* entry; cedf_domain_t* cluster; TRACE("c-edf: task new %d (param running = %d, is_running = %d)\n", t->pid, running, is_running(t)); /* the cluster doesn't change even if t is running */ cluster = task_cpu_cluster(t); raw_spin_lock_irqsave(&cluster->cluster_lock, flags); /* setup job params */ release_at(t, litmus_clock()); t->rt_param.linked_on = NO_CPU; if (running) { entry = &per_cpu(cedf_cpu_entries, task_cpu(t)); BUG_ON(entry->scheduled); #ifdef CONFIG_RELEASE_MASTER if (entry->cpu != cluster->domain.release_master) { #endif entry->scheduled = t; tsk_rt(t)->scheduled_on = task_cpu(t); #ifdef CONFIG_RELEASE_MASTER } else { /* do not schedule on release master */ preempt(entry); /* force resched */ tsk_rt(t)->scheduled_on = NO_CPU; } #endif } else { t->rt_param.scheduled_on = NO_CPU; } if (is_running(t)) { cedf_job_arrival(t); } raw_spin_unlock_irqrestore(&(cluster->cluster_lock), flags); } static void cedf_task_wake_up(struct task_struct *task) { unsigned long flags; cedf_domain_t *cluster; lt_t now = litmus_clock(); TRACE_TASK(task, "wake_up at %llu\n", now); cluster = task_cpu_cluster(task); raw_spin_lock_irqsave(&cluster->cluster_lock, flags); if (unlikely(is_persistent(task) && is_tardy(task, now))) { /* treat tardy perisistent tasks as if they were sporadic tasks by releasing a new job if they're tardy. */ release_at(task, now); sched_trace_task_release(task); } else { /* periodic task model. don't force job to end. * rely on user to say when jobs complete or when budget expires. */ tsk_rt(task)->completed = 0; } #ifdef CONFIG_REALTIME_AUX_TASKS if (tsk_rt(task)->has_aux_tasks && !tsk_rt(task)->hide_from_aux_tasks) { TRACE_CUR("%s/%d is ready so aux tasks may not inherit.\n", task->comm, task->pid); disable_aux_task_owner(task); } #endif #ifdef CONFIG_LITMUS_NVIDIA if (tsk_rt(task)->held_gpus && !tsk_rt(task)->hide_from_gpu) { TRACE_CUR("%s/%d is ready so gpu klmirqd tasks may not inherit.\n", task->comm, task->pid); disable_gpu_owner(task); } #endif cedf_job_arrival(task); raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); } static void cedf_task_block(struct task_struct *t) { unsigned long flags; cedf_domain_t *cluster; TRACE_TASK(t, "block at %llu\n", litmus_clock()); cluster = task_cpu_cluster(t); /* unlink if necessary */ raw_spin_lock_irqsave(&cluster->cluster_lock, flags); unlink(t); #ifdef CONFIG_REALTIME_AUX_TASKS if (tsk_rt(t)->has_aux_tasks && !tsk_rt(t)->hide_from_aux_tasks) { TRACE_CUR("%s/%d is blocked so aux tasks may inherit.\n", t->comm, t->pid); enable_aux_task_owner(t); } #endif #ifdef CONFIG_LITMUS_NVIDIA if (tsk_rt(t)->held_gpus && !tsk_rt(t)->hide_from_gpu) { TRACE_CUR("%s/%d is blocked so klmirqd threads may inherit.\n", t->comm, t->pid); enable_gpu_owner(t); } #endif raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); BUG_ON(!is_realtime(t)); } static void cedf_task_exit(struct task_struct * t) { unsigned long flags; cedf_domain_t *cluster = task_cpu_cluster(t); #ifdef CONFIG_LITMUS_PAI_SOFTIRQD cedf_change_prio_pai_tasklet(t, NULL); #endif /* unlink if necessary */ raw_spin_lock_irqsave(&cluster->cluster_lock, flags); #ifdef CONFIG_REALTIME_AUX_TASKS /* make sure we clean up on our way out */ if (unlikely(tsk_rt(t)->is_aux_task)) { exit_aux_task(t); } else if(tsk_rt(t)->has_aux_tasks) { disable_aux_task_owner(t); } #endif #ifdef CONFIG_LITMUS_NVIDIA /* make sure we clean up on our way out */ if(tsk_rt(t)->held_gpus) { disable_gpu_owner(t); } #endif unlink(t); if (tsk_rt(t)->scheduled_on != NO_CPU) { cpu_entry_t *cpu; cpu = &per_cpu(cedf_cpu_entries, tsk_rt(t)->scheduled_on); cpu->scheduled = NULL; tsk_rt(t)->scheduled_on = NO_CPU; } raw_spin_unlock_irqrestore(&cluster->cluster_lock, flags); BUG_ON(!is_realtime(t)); TRACE_TASK(t, "RIP\n"); } static long cedf_admit_task(struct task_struct* tsk) { #ifdef CONFIG_LITMUS_NESTED_LOCKING INIT_BINHEAP_HANDLE(&tsk_rt(tsk)->hp_blocked_tasks, edf_max_heap_base_priority_order); #endif return (task_cpu(tsk) == tsk->rt_param.task_params.cpu) ? 0 : -EINVAL; } #ifdef CONFIG_LITMUS_LOCKING #include /* called with IRQs off */ static int __increase_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh) { int success = 1; int linked_on; int check_preempt = 0; cedf_domain_t* cluster; if (prio_inh && (effective_priority(prio_inh) != prio_inh)) { TRACE_TASK(t, "Inheriting from %s/%d instead of the eff_prio = %s/%d!\n", prio_inh->comm, prio_inh->pid, effective_priority(prio_inh)->comm, effective_priority(prio_inh)->pid); #ifndef CONFIG_LITMUS_NESTED_LOCKING /* Tasks should only inherit the base priority of a task. If 't' inherits a priority, then tsk_rt(t)->inh_task should be passed to this function instead. This includes transitive inheritance relations (tsk_rt(tsk_rt(...)->inh_task)->inh_task). */ BUG(); #else /* Not a bug with nested locking since inheritance propagation is not atomic. */ /* TODO: Is the following 'helping' short-cut safe? prio_inh = effective_priority(prio_inh); */ #endif } if (prio_inh && prio_inh == effective_priority(t)) { /* relationship already established. */ TRACE_TASK(t, "already has effective priority of %s/%d\n", prio_inh->comm, prio_inh->pid); goto out; } cluster = task_cpu_cluster(t); #ifdef CONFIG_LITMUS_NESTED_LOCKING /* this sanity check allows for weaker locking in protocols */ /* TODO (klmirqd): Skip this check if 't' is a proxy thread (???) */ if(__edf_higher_prio(prio_inh, BASE, t, EFFECTIVE)) { #endif TRACE_TASK(t, "inherits priority from %s/%d\n", prio_inh->comm, prio_inh->pid); tsk_rt(t)->inh_task = prio_inh; linked_on = tsk_rt(t)->linked_on; /* If it is scheduled, then we need to reorder the CPU heap. */ if (linked_on != NO_CPU) { TRACE_TASK(t, "%s: linked on %d\n", __FUNCTION__, linked_on); /* Holder is scheduled; need to re-order CPUs. * We can't use heap_decrease() here since * the cpu_heap is ordered in reverse direction, so * it is actually an increase. */ binheap_delete(&per_cpu(cedf_cpu_entries, linked_on).hn, &cluster->cpu_heap); binheap_add(&per_cpu(cedf_cpu_entries, linked_on).hn, &cluster->cpu_heap, cpu_entry_t, hn); } else { /* holder may be queued: first stop queue changes */ raw_spin_lock(&cluster->domain.release_lock); if (is_queued(t)) { TRACE_TASK(t, "%s: is queued\n", __FUNCTION__); /* We need to update the position of holder in some * heap. Note that this could be a release heap if we * budget enforcement is used and this job overran. */ check_preempt = !bheap_decrease(edf_ready_order, tsk_rt(t)->heap_node); } else { /* Nothing to do: if it is not queued and not linked * then it is either sleeping or currently being moved * by other code (e.g., a timer interrupt handler) that * will use the correct priority when enqueuing the * task. */ TRACE_TASK(t, "%s: is NOT queued => Done.\n", __FUNCTION__); } raw_spin_unlock(&cluster->domain.release_lock); #ifdef CONFIG_REALTIME_AUX_TASKS /* propagate to aux tasks */ if (tsk_rt(t)->has_aux_tasks) { aux_task_owner_increase_priority(t); } #endif #ifdef CONFIG_LITMUS_NVIDIA /* propagate to gpu klmirqd */ if (tsk_rt(t)->held_gpus) { gpu_owner_increase_priority(t); } #endif /* If holder was enqueued in a release heap, then the following * preemption check is pointless, but we can't easily detect * that case. If you want to fix this, then consider that * simply adding a state flag requires O(n) time to update when * releasing n tasks, which conflicts with the goal to have * O(log n) merges. */ if (check_preempt) { /* heap_decrease() hit the top level of the heap: make * sure preemption checks get the right task, not the * potentially stale cache. */ bheap_uncache_min(edf_ready_order, &cluster->domain.ready_queue); check_for_preemptions(cluster); } } #ifdef CONFIG_LITMUS_NESTED_LOCKING } else { TRACE_TASK(t, "Spurious invalid priority increase. " "Inheritance request: %s/%d [eff_prio = %s/%d] to inherit from %s/%d\n" "Occurance is likely okay: probably due to (hopefully safe) concurrent priority updates.\n", t->comm, t->pid, effective_priority(t)->comm, effective_priority(t)->pid, (prio_inh) ? prio_inh->comm : "null", (prio_inh) ? prio_inh->pid : 0); WARN_ON(!prio_inh); success = 0; } #endif out: return success; } /* called with IRQs off */ static void increase_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh) { cedf_domain_t* cluster = task_cpu_cluster(t); raw_spin_lock(&cluster->cluster_lock); TRACE_TASK(t, "to inherit from %s/%d\n", prio_inh->comm, prio_inh->pid); __increase_priority_inheritance(t, prio_inh); raw_spin_unlock(&cluster->cluster_lock); #if defined(CONFIG_LITMUS_PAI_SOFTIRQD) && defined(CONFIG_LITMUS_NVIDIA) if(tsk_rt(t)->held_gpus) { int i; for(i = find_first_bit(&tsk_rt(t)->held_gpus, sizeof(tsk_rt(t)->held_gpus)); i < NV_DEVICE_NUM; i = find_next_bit(&tsk_rt(t)->held_gpus, sizeof(tsk_rt(t)->held_gpus), i+1)) { pai_check_priority_increase(t, i); } } #endif } /* called with IRQs off */ static int __decrease_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh) { int success = 1; if (prio_inh && (effective_priority(prio_inh) != prio_inh)) { TRACE_TASK(t, "Inheriting from %s/%d instead of the eff_prio = %s/%d!\n", prio_inh->comm, prio_inh->pid, effective_priority(prio_inh)->comm, effective_priority(prio_inh)->pid); #ifndef CONFIG_LITMUS_NESTED_LOCKING /* Tasks should only inherit the base priority of a task. If 't' inherits a priority, then tsk_rt(t)->inh_task should be passed to this function instead. This includes transitive inheritance relations (tsk_rt(tsk_rt(...)->inh_task)->inh_task). */ BUG(); #else /* Not a bug with nested locking since inheritance propagation is not atomic. */ /* TODO: Is the following 'helping' short-cut safe? prio_inh = effective_priority(prio_inh); */ #endif } if (prio_inh == tsk_rt(t)->inh_task) { /* relationship already established. */ TRACE_TASK(t, "already inherits priority from %s/%d\n", (prio_inh) ? prio_inh->comm : "(null)", (prio_inh) ? prio_inh->pid : 0); goto out; } #ifdef CONFIG_LITMUS_NESTED_LOCKING if(__edf_higher_prio(t, EFFECTIVE, prio_inh, BASE)) { #endif /* A job only stops inheriting a priority when it releases a * resource. Thus we can make the following assumption.*/ if(prio_inh) TRACE_TASK(t, "EFFECTIVE priority decreased to %s/%d\n", prio_inh->comm, prio_inh->pid); else TRACE_TASK(t, "base priority restored.\n"); tsk_rt(t)->inh_task = prio_inh; if(tsk_rt(t)->scheduled_on != NO_CPU) { TRACE_TASK(t, "is scheduled.\n"); /* Check if rescheduling is necessary. We can't use heap_decrease() * since the priority was effectively lowered. */ unlink(t); cedf_job_arrival(t); } else { cedf_domain_t* cluster = task_cpu_cluster(t); /* task is queued */ raw_spin_lock(&cluster->domain.release_lock); if (is_queued(t)) { TRACE_TASK(t, "is queued.\n"); /* decrease in priority, so we have to re-add to binomial heap */ unlink(t); cedf_job_arrival(t); } else { TRACE_TASK(t, "is not in scheduler. Probably on wait queue somewhere.\n"); } raw_spin_unlock(&cluster->domain.release_lock); } #ifdef CONFIG_REALTIME_AUX_TASKS /* propagate to aux tasks */ if (tsk_rt(t)->has_aux_tasks) { aux_task_owner_decrease_priority(t); } #endif #ifdef CONFIG_LITMUS_NVIDIA /* propagate to gpu */ if (tsk_rt(t)->held_gpus) { gpu_owner_decrease_priority(t); } #endif #ifdef CONFIG_LITMUS_NESTED_LOCKING } else { TRACE_TASK(t, "Spurious invalid priority decrease. " "Inheritance request: %s/%d [eff_prio = %s/%d] to inherit from %s/%d\n" "Occurance is likely okay: probably due to (hopefully safe) concurrent priority updates.\n", t->comm, t->pid, effective_priority(t)->comm, effective_priority(t)->pid, (prio_inh) ? prio_inh->comm : "null", (prio_inh) ? prio_inh->pid : 0); success = 0; } #endif out: return success; } static void decrease_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh) { cedf_domain_t* cluster = task_cpu_cluster(t); raw_spin_lock(&cluster->cluster_lock); TRACE_TASK(t, "to inherit from %s/%d (decrease)\n", (prio_inh) ? prio_inh->comm : "null", (prio_inh) ? prio_inh->pid : 0); __decrease_priority_inheritance(t, prio_inh); raw_spin_unlock(&cluster->cluster_lock); #if defined(CONFIG_LITMUS_PAI_SOFTIRQD) && defined(CONFIG_LITMUS_NVIDIA) if(tsk_rt(t)->held_gpus) { int i; for(i = find_first_bit(&tsk_rt(t)->held_gpus, sizeof(tsk_rt(t)->held_gpus)); i < NV_DEVICE_NUM; i = find_next_bit(&tsk_rt(t)->held_gpus, sizeof(tsk_rt(t)->held_gpus), i+1)) { pai_check_priority_decrease(t, i); } } #endif } #ifdef CONFIG_LITMUS_NESTED_LOCKING /* called with IRQs off */ /* preconditions: (1) The 'hp_blocked_tasks_lock' of task 't' is held. (2) The lock 'to_unlock' is held. */ static void nested_increase_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh, raw_spinlock_t *to_unlock, unsigned long irqflags) { struct litmus_lock *blocked_lock = tsk_rt(t)->blocked_lock; if(tsk_rt(t)->inh_task != prio_inh) { // shield redundent calls. increase_priority_inheritance(t, prio_inh); // increase our prio. } /* note: cluster lock is not held continuously during propagation, so there may be momentary inconsistencies while nested priority propagation 'chases' other updates. */ raw_spin_unlock(&tsk_rt(t)->hp_blocked_tasks_lock); // unlock the t's heap. if(blocked_lock) { if(blocked_lock->ops->propagate_increase_inheritance) { TRACE_TASK(t, "Inheritor is blocked (...perhaps). Checking lock %d.\n", blocked_lock->ident); // beware: recursion blocked_lock->ops->propagate_increase_inheritance(blocked_lock, t, to_unlock, irqflags); } else { TRACE_TASK(t, "Inheritor is blocked on lock (%d) that does not support nesting!\n", blocked_lock->ident); unlock_fine_irqrestore(to_unlock, irqflags); } } else { TRACE_TASK(t, "is not blocked. No propagation.\n"); unlock_fine_irqrestore(to_unlock, irqflags); } } /* called with IRQs off */ /* preconditions: (1) The 'hp_blocked_tasks_lock' of task 't' is held. (2) The lock 'to_unlock' is held. */ static void nested_decrease_priority_inheritance(struct task_struct* t, struct task_struct* prio_inh, raw_spinlock_t *to_unlock, unsigned long irqflags) { struct litmus_lock *blocked_lock = tsk_rt(t)->blocked_lock; decrease_priority_inheritance(t, prio_inh); raw_spin_unlock(&tsk_rt(t)->hp_blocked_tasks_lock); // unlock the t's heap. if(blocked_lock) { if(blocked_lock->ops->propagate_decrease_inheritance) { TRACE_TASK(t, "Inheritor is blocked (...perhaps). Checking lock %d.\n", blocked_lock->ident); // beware: recursion blocked_lock->ops->propagate_decrease_inheritance(blocked_lock, t, to_unlock, irqflags); } else { TRACE_TASK(t, "Inheritor is blocked on lock (%p) that does not support nesting!\n", blocked_lock); unlock_fine_irqrestore(to_unlock, irqflags); } } else { TRACE_TASK(t, "is not blocked. No propagation.\n"); unlock_fine_irqrestore(to_unlock, irqflags); } } /* ******************** FIFO MUTEX ********************** */ static struct litmus_lock_ops cedf_fifo_mutex_lock_ops = { .lock = fifo_mutex_lock, .unlock = fifo_mutex_unlock, .close = fifo_mutex_close, .deallocate = fifo_mutex_free, .propagate_increase_inheritance = fifo_mutex_propagate_increase_inheritance, .propagate_decrease_inheritance = fifo_mutex_propagate_decrease_inheritance, #ifdef CONFIG_LITMUS_DGL_SUPPORT .dgl_lock = fifo_mutex_dgl_lock, .is_owner = fifo_mutex_is_owner, .enable_priority = fifo_mutex_enable_priority, #endif }; static struct litmus_lock* cedf_new_fifo_mutex(void) { return fifo_mutex_new(&cedf_fifo_mutex_lock_ops); } /* ******************** PRIOQ MUTEX ********************** */ static struct litmus_lock_ops cedf_prioq_mutex_lock_ops = { .lock = prioq_mutex_lock, .unlock = prioq_mutex_unlock, .close = prioq_mutex_close, .deallocate = prioq_mutex_free, .propagate_increase_inheritance = prioq_mutex_propagate_increase_inheritance, .propagate_decrease_inheritance = prioq_mutex_propagate_decrease_inheritance, #ifdef CONFIG_LITMUS_DGL_SUPPORT .dgl_lock = prioq_mutex_dgl_lock, .is_owner = prioq_mutex_is_owner, .enable_priority = prioq_mutex_enable_priority, .dgl_can_quick_lock = prioq_mutex_dgl_can_quick_lock, .dgl_quick_lock = prioq_mutex_dgl_quick_lock, #endif }; static struct litmus_lock* cedf_new_prioq_mutex(void) { return prioq_mutex_new(&cedf_prioq_mutex_lock_ops); } /* ******************** IKGLP ********************** */ static struct litmus_lock_ops cedf_ikglp_lock_ops = { .lock = ikglp_lock, .unlock = ikglp_unlock, .close = ikglp_close, .deallocate = ikglp_free, // ikglp can only be an outer-most lock. .propagate_increase_inheritance = NULL, .propagate_decrease_inheritance = NULL, }; static struct litmus_lock* cedf_new_ikglp(void* __user arg) { // assumes clusters of uniform size. return ikglp_new(cluster_size, &cedf_ikglp_lock_ops, arg); } #endif /* CONFIG_LITMUS_NESTED_LOCKING */ /* ******************** KFMLP support ********************** */ static struct litmus_lock_ops cedf_kfmlp_lock_ops = { .lock = kfmlp_lock, .unlock = kfmlp_unlock, .close = kfmlp_close, .deallocate = kfmlp_free, // kfmlp can only be an outer-most lock. .propagate_increase_inheritance = NULL, .propagate_decrease_inheritance = NULL, }; static struct litmus_lock* cedf_new_kfmlp(void* __user arg) { return kfmlp_new(&cedf_kfmlp_lock_ops, arg); } /* **** lock constructor **** */ static long cedf_allocate_lock(struct litmus_lock **lock, int type, void* __user args) { int err; switch (type) { #ifdef CONFIG_LITMUS_NESTED_LOCKING case FIFO_MUTEX: *lock = cedf_new_fifo_mutex(); break; case PRIOQ_MUTEX: *lock = cedf_new_prioq_mutex(); break; case IKGLP_SEM: *lock = cedf_new_ikglp(args); break; #endif case KFMLP_SEM: *lock = cedf_new_kfmlp(args); break; default: err = -ENXIO; goto UNSUPPORTED_LOCK; }; if (*lock) err = 0; else err = -ENOMEM; UNSUPPORTED_LOCK: return err; } #endif // CONFIG_LITMUS_LOCKING #ifdef CONFIG_LITMUS_AFFINITY_LOCKING static struct affinity_observer_ops cedf_kfmlp_affinity_ops __attribute__ ((unused)) = { .close = kfmlp_aff_obs_close, .deallocate = kfmlp_aff_obs_free, }; #ifdef CONFIG_LITMUS_NESTED_LOCKING static struct affinity_observer_ops cedf_ikglp_affinity_ops __attribute__ ((unused)) = { .close = ikglp_aff_obs_close, .deallocate = ikglp_aff_obs_free, }; #endif static long cedf_allocate_affinity_observer(struct affinity_observer **aff_obs, int type, void* __user args) { int err; switch (type) { #ifdef CONFIG_LITMUS_NVIDIA case KFMLP_SIMPLE_GPU_AFF_OBS: *aff_obs = kfmlp_simple_gpu_aff_obs_new(&cedf_kfmlp_affinity_ops, args); break; case KFMLP_GPU_AFF_OBS: *aff_obs = kfmlp_gpu_aff_obs_new(&cedf_kfmlp_affinity_ops, args); break; #ifdef CONFIG_LITMUS_NESTED_LOCKING case IKGLP_SIMPLE_GPU_AFF_OBS: *aff_obs = ikglp_simple_gpu_aff_obs_new(&cedf_ikglp_affinity_ops, args); break; case IKGLP_GPU_AFF_OBS: *aff_obs = ikglp_gpu_aff_obs_new(&cedf_ikglp_affinity_ops, args); break; #endif #endif default: err = -ENXIO; goto UNSUPPORTED_AFF_OBS; }; if (*aff_obs) err = 0; else err = -ENOMEM; UNSUPPORTED_AFF_OBS: return err; } #endif #ifdef VERBOSE_INIT static void print_cluster_topology(cpumask_var_t mask, int cpu) { int chk; char buf[255]; chk = cpulist_scnprintf(buf, 254, mask); buf[chk] = '\0'; printk(KERN_INFO "CPU = %d, shared cpu(s) = %s\n", cpu, buf); } #endif static void cleanup_cedf(void) { int i; if (clusters_allocated) { for (i = 0; i < num_clusters; i++) { kfree(cedf[i].cpus); free_cpumask_var(cedf[i].cpu_map); } kfree(cedf); } } #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD) static int cedf_map_gpu_to_cpu(int gpu) { int default_cpu; int cpu_cluster = gpu / gpu_cluster_size; /* bonham-specific hack for the fully partitioned case (both CPUs and GPUs partitioned) */ /* TODO: Make this aware of the NUMA topology generically */ if(num_clusters == 12 && num_gpu_clusters == 8) { if(gpu >= 4) { cpu_cluster += 2; // assign the GPU to a CPU on the same NUMA node } } default_cpu = cedf[cpu_cluster].cpus[0]->cpu; // first CPU in given cluster TRACE("CPU %d is default for GPU %d interrupt threads.\n", default_cpu, gpu); return default_cpu; } #endif static long cedf_activate_plugin(void) { int i, j, cpu, ccpu, cpu_count; cpu_entry_t *entry; cpumask_var_t mask; int chk = 0; /* de-allocate old clusters, if any */ cleanup_cedf(); printk(KERN_INFO "C-EDF: Activate Plugin, cluster configuration = %d\n", cluster_config); /* need to get cluster_size first */ if(!zalloc_cpumask_var(&mask, GFP_ATOMIC)) return -ENOMEM; if (unlikely(cluster_config == GLOBAL_CLUSTER)) { cluster_size = num_online_cpus(); } else { chk = get_shared_cpu_map(mask, 0, cluster_config); if (chk) { /* if chk != 0 then it is the max allowed index */ printk(KERN_INFO "C-EDF: Cluster configuration = %d " "is not supported on this hardware.\n", cluster_config); /* User should notice that the configuration failed, so * let's bail out. */ return -EINVAL; } cluster_size = cpumask_weight(mask); } if ((num_online_cpus() % cluster_size) != 0) { /* this can't be right, some cpus are left out */ printk(KERN_ERR "C-EDF: Trying to group %d cpus in %d!\n", num_online_cpus(), cluster_size); return -1; } num_clusters = num_online_cpus() / cluster_size; printk(KERN_INFO "C-EDF: %d cluster(s) of size = %d\n", num_clusters, cluster_size); #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD) num_gpu_clusters = min(num_clusters, num_online_gpus()); gpu_cluster_size = num_online_gpus() / num_gpu_clusters; if (((num_online_gpus() % gpu_cluster_size) != 0) || (num_gpu_clusters != num_clusters)) { printk(KERN_WARNING "C-EDF: GPUs not uniformly distributed among CPU clusters.\n"); } #endif /* initialize clusters */ cedf = kmalloc(num_clusters * sizeof(cedf_domain_t), GFP_ATOMIC); for (i = 0; i < num_clusters; i++) { cedf[i].cpus = kmalloc(cluster_size * sizeof(cpu_entry_t), GFP_ATOMIC); INIT_BINHEAP_HANDLE(&(cedf[i].cpu_heap), cpu_lower_prio); edf_domain_init(&(cedf[i].domain), NULL, cedf_release_jobs); #ifdef CONFIG_LITMUS_PAI_SOFTIRQD cedf[i].pending_tasklets.head = NULL; cedf[i].pending_tasklets.tail = &(cedf[i].pending_tasklets.head); #endif if(!zalloc_cpumask_var(&cedf[i].cpu_map, GFP_ATOMIC)) return -ENOMEM; #ifdef CONFIG_RELEASE_MASTER cedf[i].domain.release_master = atomic_read(&release_master_cpu); #endif } /* cycle through cluster and add cpus to them */ for (i = 0; i < num_clusters; i++) { #ifdef CONFIG_LITMUS_DGL_SUPPORT raw_spin_lock_init(&cedf[i].dgl_lock); #endif for_each_online_cpu(cpu) { /* check if the cpu is already in a cluster */ for (j = 0; j < num_clusters; j++) if (cpumask_test_cpu(cpu, cedf[j].cpu_map)) break; /* if it is in a cluster go to next cpu */ if (j < num_clusters && cpumask_test_cpu(cpu, cedf[j].cpu_map)) continue; /* this cpu isn't in any cluster */ /* get the shared cpus */ if (unlikely(cluster_config == GLOBAL_CLUSTER)) cpumask_copy(mask, cpu_online_mask); else get_shared_cpu_map(mask, cpu, cluster_config); cpumask_copy(cedf[i].cpu_map, mask); #ifdef VERBOSE_INIT print_cluster_topology(mask, cpu); #endif /* add cpus to current cluster and init cpu_entry_t */ cpu_count = 0; for_each_cpu(ccpu, cedf[i].cpu_map) { entry = &per_cpu(cedf_cpu_entries, ccpu); cedf[i].cpus[cpu_count] = entry; atomic_set(&entry->will_schedule, 0); entry->cpu = ccpu; entry->cluster = &cedf[i]; INIT_BINHEAP_NODE(&entry->hn); cpu_count++; entry->linked = NULL; entry->scheduled = NULL; #ifdef CONFIG_RELEASE_MASTER /* only add CPUs that should schedule jobs */ if (entry->cpu != entry->cluster->domain.release_master) #endif update_cpu_position(entry); } /* done with this cluster */ break; } } #ifdef CONFIG_LITMUS_SOFTIRQD init_klmirqd(); #endif #ifdef CONFIG_LITMUS_NVIDIA init_nvidia_info(); #endif free_cpumask_var(mask); clusters_allocated = 1; return 0; } /* Plugin object */ static struct sched_plugin cedf_plugin __cacheline_aligned_in_smp = { .plugin_name = "C-EDF", .finish_switch = cedf_finish_switch, .tick = cedf_tick, .task_new = cedf_task_new, .complete_job = complete_job, .task_exit = cedf_task_exit, .schedule = cedf_schedule, .task_wake_up = cedf_task_wake_up, .task_block = cedf_task_block, .admit_task = cedf_admit_task, .activate_plugin = cedf_activate_plugin, .compare = edf_higher_prio, #ifdef CONFIG_LITMUS_LOCKING .allocate_lock = cedf_allocate_lock, .increase_prio = increase_priority_inheritance, .decrease_prio = decrease_priority_inheritance, .__increase_prio = __increase_priority_inheritance, .__decrease_prio = __decrease_priority_inheritance, #endif #ifdef CONFIG_LITMUS_NESTED_LOCKING .nested_increase_prio = nested_increase_priority_inheritance, .nested_decrease_prio = nested_decrease_priority_inheritance, .__compare = __edf_higher_prio, #endif #ifdef CONFIG_LITMUS_DGL_SUPPORT .get_dgl_spinlock = cedf_get_dgl_spinlock, #endif #ifdef CONFIG_LITMUS_AFFINITY_LOCKING .allocate_aff_obs = cedf_allocate_affinity_observer, #endif #ifdef CONFIG_LITMUS_PAI_SOFTIRQD .enqueue_pai_tasklet = cedf_enqueue_pai_tasklet, .change_prio_pai_tasklet = cedf_change_prio_pai_tasklet, .run_tasklets = cedf_run_tasklets, #endif #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD) .map_gpu_to_cpu = cedf_map_gpu_to_cpu, #endif }; static struct proc_dir_entry *cluster_file = NULL, *cedf_dir = NULL; static int __init init_cedf(void) { int err, fs; err = register_sched_plugin(&cedf_plugin); if (!err) { fs = make_plugin_proc_dir(&cedf_plugin, &cedf_dir); if (!fs) cluster_file = create_cluster_file(cedf_dir, &cluster_config); else printk(KERN_ERR "Could not allocate C-EDF procfs dir.\n"); } return err; } static void clean_cedf(void) { cleanup_cedf(); if (cluster_file) remove_proc_entry("cluster", cedf_dir); if (cedf_dir) remove_plugin_proc_dir(&cedf_plugin); } module_init(init_cedf); module_exit(clean_cedf);