/* sched.c - SPU scheduler. * * Copyright (C) IBM 2005 * Author: Mark Nutter * * 2006-03-31 NUMA domains added. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "spufs.h" struct spu_prio_array { DECLARE_BITMAP(bitmap, MAX_PRIO); struct list_head runq[MAX_PRIO]; spinlock_t runq_lock; int nr_waiting; }; static unsigned long spu_avenrun[3]; static struct spu_prio_array *spu_prio; static struct task_struct *spusched_task; static struct timer_list spusched_timer; static struct timer_list spuloadavg_timer; /* * Priority of a normal, non-rt, non-niced'd process (aka nice level 0). */ #define NORMAL_PRIO 120 /* * Frequency of the spu scheduler tick. By default we do one SPU scheduler * tick for every 10 CPU scheduler ticks. */ #define SPUSCHED_TICK (10) /* * These are the 'tuning knobs' of the scheduler: * * Minimum timeslice is 5 msecs (or 1 spu scheduler tick, whichever is * larger), default timeslice is 100 msecs, maximum timeslice is 800 msecs. */ #define MIN_SPU_TIMESLICE max(5 * HZ / (1000 * SPUSCHED_TICK), 1) #define DEF_SPU_TIMESLICE (100 * HZ / (1000 * SPUSCHED_TICK)) #define MAX_USER_PRIO (MAX_PRIO - MAX_RT_PRIO) #define SCALE_PRIO(x, prio) \ max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE) /* * scale user-nice values [ -20 ... 0 ... 19 ] to time slice values: * [800ms ... 100ms ... 5ms] * * The higher a thread's priority, the bigger timeslices * it gets during one round of execution. But even the lowest * priority thread gets MIN_TIMESLICE worth of execution time. */ void spu_set_timeslice(struct spu_context *ctx) { if (ctx->prio < NORMAL_PRIO) ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE * 4, ctx->prio); else ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE, ctx->prio); } /* * Update scheduling information from the owning thread. */ void __spu_update_sched_info(struct spu_context *ctx) { /* * assert that the context is not on the runqueue, so it is safe * to change its scheduling parameters. */ BUG_ON(!list_empty(&ctx->rq)); /* * 32-Bit assignments are atomic on powerpc, and we don't care about * memory ordering here because retrieving the controlling thread is * per definition racy. */ ctx->tid = current->pid; /* * We do our own priority calculations, so we normally want * ->static_prio to start with. Unfortunately this field * contains junk for threads with a realtime scheduling * policy so we have to look at ->prio in this case. */ if (rt_prio(current->prio)) ctx->prio = current->prio; else ctx->prio = current->static_prio; ctx->policy = current->policy; /* * TO DO: the context may be loaded, so we may need to activate * it again on a different node. But it shouldn't hurt anything * to update its parameters, because we know that the scheduler * is not actively looking at this field, since it is not on the * runqueue. The context will be rescheduled on the proper node * if it is timesliced or preempted. */ ctx->cpus_allowed = current->cpus_allowed; /* Save the current cpu id for spu interrupt routing. */ ctx->last_ran = raw_smp_processor_id(); } void spu_update_sched_info(struct spu_context *ctx) { int node; if (ctx->state == SPU_STATE_RUNNABLE) { node = ctx->spu->node; /* * Take list_mutex to sync with find_victim(). */ mutex_lock(&cbe_spu_info[node].list_mutex); __spu_update_sched_info(ctx); mutex_unlock(&cbe_spu_info[node].list_mutex); } else { __spu_update_sched_info(ctx); } } static int __node_allowed(struct spu_context *ctx, int node) { if (nr_cpus_node(node)) { cpumask_t mask = node_to_cpumask(node); if (cpus_intersects(mask, ctx->cpus_allowed)) return 1; } return 0; } static int node_allowed(struct spu_context *ctx, int node) { int rval; spin_lock(&spu_prio->runq_lock); rval = __node_allowed(ctx, node); spin_unlock(&spu_prio->runq_lock); return rval; } void do_notify_spus_active(void) { int node; /* * Wake up the active spu_contexts. * * When the awakened processes see their "notify_active" flag is set, * they will call spu_switch_notify(). */ for_each_online_node(node) { struct spu *spu; mutex_lock(&cbe_spu_info[node].list_mutex); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { if (spu->alloc_state != SPU_FREE) { struct spu_context *ctx = spu->ctx; set_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags); mb(); wake_up_all(&ctx->stop_wq); } } mutex_unlock(&cbe_spu_info[node].list_mutex); } } /** * spu_bind_context - bind spu context to physical spu * @spu: physical spu to bind to * @ctx: context to bind */ static void spu_bind_context(struct spu *spu, struct spu_context *ctx) { spu_context_trace(spu_bind_context__enter, ctx, spu); spuctx_switch_state(ctx, SPU_UTIL_SYSTEM); if (ctx->flags & SPU_CREATE_NOSCHED) atomic_inc(&cbe_spu_info[spu->node].reserved_spus); ctx->stats.slb_flt_base = spu->stats.slb_flt; ctx->stats.class2_intr_base = spu->stats.class2_intr; spu_associate_mm(spu, ctx->owner); spin_lock_irq(&spu->register_lock); spu->ctx = ctx; spu->flags = 0; ctx->spu = spu; ctx->ops = &spu_hw_ops; spu->pid = current->pid; spu->tgid = current->tgid; spu->ibox_callback = spufs_ibox_callback; spu->wbox_callback = spufs_wbox_callback; spu->stop_callback = spufs_stop_callback; spu->mfc_callback = spufs_mfc_callback; spin_unlock_irq(&spu->register_lock); spu_unmap_mappings(ctx); spu_switch_log_notify(spu, ctx, SWITCH_LOG_START, 0); spu_restore(&ctx->csa, spu); spu->timestamp = jiffies; spu_switch_notify(spu, ctx); ctx->state = SPU_STATE_RUNNABLE; spuctx_switch_state(ctx, SPU_UTIL_USER); } /* * Must be used with the list_mutex held. */ static inline int sched_spu(struct spu *spu) { BUG_ON(!mutex_is_locked(&cbe_spu_info[spu->node].list_mutex)); return (!spu->ctx || !(spu->ctx->flags & SPU_CREATE_NOSCHED)); } static void aff_merge_remaining_ctxs(struct spu_gang *gang) { struct spu_context *ctx; list_for_each_entry(ctx, &gang->aff_list_head, aff_list) { if (list_empty(&ctx->aff_list)) list_add(&ctx->aff_list, &gang->aff_list_head); } gang->aff_flags |= AFF_MERGED; } static void aff_set_offsets(struct spu_gang *gang) { struct spu_context *ctx; int offset; offset = -1; list_for_each_entry_reverse(ctx, &gang->aff_ref_ctx->aff_list, aff_list) { if (&ctx->aff_list == &gang->aff_list_head) break; ctx->aff_offset = offset--; } offset = 0; list_for_each_entry(ctx, gang->aff_ref_ctx->aff_list.prev, aff_list) { if (&ctx->aff_list == &gang->aff_list_head) break; ctx->aff_offset = offset++; } gang->aff_flags |= AFF_OFFSETS_SET; } static struct spu *aff_ref_location(struct spu_context *ctx, int mem_aff, int group_size, int lowest_offset) { struct spu *spu; int node, n; /* * TODO: A better algorithm could be used to find a good spu to be * used as reference location for the ctxs chain. */ node = cpu_to_node(raw_smp_processor_id()); for (n = 0; n < MAX_NUMNODES; n++, node++) { int available_spus; node = (node < MAX_NUMNODES) ? node : 0; if (!node_allowed(ctx, node)) continue; available_spus = 0; mutex_lock(&cbe_spu_info[node].list_mutex); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { if (spu->ctx && spu->ctx->gang && spu->ctx->aff_offset == 0) available_spus -= (spu->ctx->gang->contexts - 1); else available_spus++; } if (available_spus < ctx->gang->contexts) { mutex_unlock(&cbe_spu_info[node].list_mutex); continue; } list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { if ((!mem_aff || spu->has_mem_affinity) && sched_spu(spu)) { mutex_unlock(&cbe_spu_info[node].list_mutex); return spu; } } mutex_unlock(&cbe_spu_info[node].list_mutex); } return NULL; } static void aff_set_ref_point_location(struct spu_gang *gang) { int mem_aff, gs, lowest_offset; struct spu_context *ctx; struct spu *tmp; mem_aff = gang->aff_ref_ctx->flags & SPU_CREATE_AFFINITY_MEM; lowest_offset = 0; gs = 0; list_for_each_entry(tmp, &gang->aff_list_head, aff_list) gs++; list_for_each_entry_reverse(ctx, &gang->aff_ref_ctx->aff_list, aff_list) { if (&ctx->aff_list == &gang->aff_list_head) break; lowest_offset = ctx->aff_offset; } gang->aff_ref_spu = aff_ref_location(gang->aff_ref_ctx, mem_aff, gs, lowest_offset); } static struct spu *ctx_location(struct spu *ref, int offset, int node) { struct spu *spu; spu = NULL; if (offset >= 0) { list_for_each_entry(spu, ref->aff_list.prev, aff_list) { BUG_ON(spu->node != node); if (offset == 0) break; if (sched_spu(spu)) offset--; } } else { list_for_each_entry_reverse(spu, ref->aff_list.next, aff_list) { BUG_ON(spu->node != node); if (offset == 0) break; if (sched_spu(spu)) offset++; } } return spu; } /* * affinity_check is called each time a context is going to be scheduled. * It returns the spu ptr on which the context must run. */ static int has_affinity(struct spu_context *ctx) { struct spu_gang *gang = ctx->gang; if (list_empty(&ctx->aff_list)) return 0; if (atomic_read(&ctx->gang->aff_sched_count) == 0) ctx->gang->aff_ref_spu = NULL; if (!gang->aff_ref_spu) { if (!(gang->aff_flags & AFF_MERGED)) aff_merge_remaining_ctxs(gang); if (!(gang->aff_flags & AFF_OFFSETS_SET)) aff_set_offsets(gang); aff_set_ref_point_location(gang); } return gang->aff_ref_spu != NULL; } /** * spu_unbind_context - unbind spu context from physical spu * @spu: physical spu to unbind from * @ctx: context to unbind */ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx) { u32 status; spu_context_trace(spu_unbind_context__enter, ctx, spu); spuctx_switch_state(ctx, SPU_UTIL_SYSTEM); if (spu->ctx->flags & SPU_CREATE_NOSCHED) atomic_dec(&cbe_spu_info[spu->node].reserved_spus); if (ctx->gang) atomic_dec_if_positive(&ctx->gang->aff_sched_count); spu_switch_notify(spu, NULL); spu_unmap_mappings(ctx); spu_save(&ctx->csa, spu); spu_switch_log_notify(spu, ctx, SWITCH_LOG_STOP, 0); spin_lock_irq(&spu->register_lock); spu->timestamp = jiffies; ctx->state = SPU_STATE_SAVED; spu->ibox_callback = NULL; spu->wbox_callback = NULL; spu->stop_callback = NULL; spu->mfc_callback = NULL; spu->pid = 0; spu->tgid = 0; ctx->ops = &spu_backing_ops; spu->flags = 0; spu->ctx = NULL; spin_unlock_irq(&spu->register_lock); spu_associate_mm(spu, NULL); ctx->stats.slb_flt += (spu->stats.slb_flt - ctx->stats.slb_flt_base); ctx->stats.class2_intr += (spu->stats.class2_intr - ctx->stats.class2_intr_base); /* This maps the underlying spu state to idle */ spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED); ctx->spu = NULL; if (spu_stopped(ctx, &status)) wake_up_all(&ctx->stop_wq); } /** * spu_add_to_rq - add a context to the runqueue * @ctx: context to add */ static void __spu_add_to_rq(struct spu_context *ctx) { /* * Unfortunately this code path can be called from multiple threads * on behalf of a single context due to the way the problem state * mmap support works. * * Fortunately we need to wake up all these threads at the same time * and can simply skip the runqueue addition for every but the first * thread getting into this codepath. * * It's still quite hacky, and long-term we should proxy all other * threads through the owner thread so that spu_run is in control * of all the scheduling activity for a given context. */ if (list_empty(&ctx->rq)) { list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]); set_bit(ctx->prio, spu_prio->bitmap); if (!spu_prio->nr_waiting++) __mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK); } } static void spu_add_to_rq(struct spu_context *ctx) { spin_lock(&spu_prio->runq_lock); __spu_add_to_rq(ctx); spin_unlock(&spu_prio->runq_lock); } static void __spu_del_from_rq(struct spu_context *ctx) { int prio = ctx->prio; if (!list_empty(&ctx->rq)) { if (!--spu_prio->nr_waiting) del_timer(&spusched_timer); list_del_init(&ctx->rq); if (list_empty(&spu_prio->runq[prio])) clear_bit(prio, spu_prio->bitmap); } } void spu_del_from_rq(struct spu_context *ctx) { spin_lock(&spu_prio->runq_lock); __spu_del_from_rq(ctx); spin_unlock(&spu_prio->runq_lock); } static void spu_prio_wait(struct spu_context *ctx) { DEFINE_WAIT(wait); /* * The caller must explicitly wait for a context to be loaded * if the nosched flag is set. If NOSCHED is not set, the caller * queues the context and waits for an spu event or error. */ BUG_ON(!(ctx->flags & SPU_CREATE_NOSCHED)); spin_lock(&spu_prio->runq_lock); prepare_to_wait_exclusive(&ctx->stop_wq, &wait, TASK_INTERRUPTIBLE); if (!signal_pending(current)) { __spu_add_to_rq(ctx); spin_unlock(&spu_prio->runq_lock); mutex_unlock(&ctx->state_mutex); schedule(); mutex_lock(&ctx->state_mutex); spin_lock(&spu_prio->runq_lock); __spu_del_from_rq(ctx); } spin_unlock(&spu_prio->runq_lock); __set_current_state(TASK_RUNNING); remove_wait_queue(&ctx->stop_wq, &wait); } static struct spu *spu_get_idle(struct spu_context *ctx) { struct spu *spu, *aff_ref_spu; int node, n; spu_context_nospu_trace(spu_get_idle__enter, ctx); if (ctx->gang) { mutex_lock(&ctx->gang->aff_mutex); if (has_affinity(ctx)) { aff_ref_spu = ctx->gang->aff_ref_spu; atomic_inc(&ctx->gang->aff_sched_count); mutex_unlock(&ctx->gang->aff_mutex); node = aff_ref_spu->node; mutex_lock(&cbe_spu_info[node].list_mutex); spu = ctx_location(aff_ref_spu, ctx->aff_offset, node); if (spu && spu->alloc_state == SPU_FREE) goto found; mutex_unlock(&cbe_spu_info[node].list_mutex); atomic_dec(&ctx->gang->aff_sched_count); goto not_found; } mutex_unlock(&ctx->gang->aff_mutex); } node = cpu_to_node(raw_smp_processor_id()); for (n = 0; n < MAX_NUMNODES; n++, node++) { node = (node < MAX_NUMNODES) ? node : 0; if (!node_allowed(ctx, node)) continue; mutex_lock(&cbe_spu_info[node].list_mutex); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { if (spu->alloc_state == SPU_FREE) goto found; } mutex_unlock(&cbe_spu_info[node].list_mutex); } not_found: spu_context_nospu_trace(spu_get_idle__not_found, ctx); return NULL; found: spu->alloc_state = SPU_USED; mutex_unlock(&cbe_spu_info[node].list_mutex); spu_context_trace(spu_get_idle__found, ctx, spu); spu_init_channels(spu); return spu; } /** * find_victim - find a lower priority context to preempt * @ctx: canidate context for running * * Returns the freed physical spu to run the new context on. */ static struct spu *find_victim(struct spu_context *ctx) { struct spu_context *victim = NULL; struct spu *spu; int node, n; spu_context_nospu_trace(spu_find_victim__enter, ctx); /* * Look for a possible preemption candidate on the local node first. * If there is no candidate look at the other nodes. This isn't * exactly fair, but so far the whole spu scheduler tries to keep * a strong node affinity. We might want to fine-tune this in * the future. */ restart: node = cpu_to_node(raw_smp_processor_id()); for (n = 0; n < MAX_NUMNODES; n++, node++) { node = (node < MAX_NUMNODES) ? node : 0; if (!node_allowed(ctx, node)) continue; mutex_lock(&cbe_spu_info[node].list_mutex); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { struct spu_context *tmp = spu->ctx; if (tmp && tmp->prio > ctx->prio && !(tmp->flags & SPU_CREATE_NOSCHED) && (!victim || tmp->prio > victim->prio)) { victim = spu->ctx; } } if (victim) get_spu_context(victim); mutex_unlock(&cbe_spu_info[node].list_mutex); if (victim) { /* * This nests ctx->state_mutex, but we always lock * higher priority contexts before lower priority * ones, so this is safe until we introduce * priority inheritance schemes. * * XXX if the highest priority context is locked, * this can loop a long time. Might be better to * look at another context or give up after X retries. */ if (!mutex_trylock(&victim->state_mutex)) { put_spu_context(victim); victim = NULL; goto restart; } spu = victim->spu; if (!spu || victim->prio <= ctx->prio) { /* * This race can happen because we've dropped * the active list mutex. Not a problem, just * restart the search. */ mutex_unlock(&victim->state_mutex); put_spu_context(victim); victim = NULL; goto restart; } spu_context_trace(__spu_deactivate__unload, ctx, spu); mutex_lock(&cbe_spu_info[node].list_mutex); cbe_spu_info[node].nr_active--; spu_unbind_context(spu, victim); mutex_unlock(&cbe_spu_info[node].list_mutex); victim->stats.invol_ctx_switch++; spu->stats.invol_ctx_switch++; if (test_bit(SPU_SCHED_SPU_RUN, &victim->sched_flags)) spu_add_to_rq(victim); mutex_unlock(&victim->state_mutex); put_spu_context(victim); return spu; } } return NULL; } static void __spu_schedule(struct spu *spu, struct spu_context *ctx) { int node = spu->node; int success = 0; spu_set_timeslice(ctx); mutex_lock(&cbe_spu_info[node].list_mutex); if (spu->ctx == NULL) { spu_bind_context(spu, ctx); cbe_spu_info[node].nr_active++; spu->alloc_state = SPU_USED; success = 1; } mutex_unlock(&cbe_spu_info[node].list_mutex); if (success) wake_up_all(&ctx->run_wq); else spu_add_to_rq(ctx); } static void spu_schedule(struct spu *spu, struct spu_context *ctx) { /* not a candidate for interruptible because it's called either from the scheduler thread or from spu_deactivate */ mutex_lock(&ctx->state_mutex); __spu_schedule(spu, ctx); spu_release(ctx); } static void spu_unschedule(struct spu *spu, struct spu_context *ctx) { int node = spu->node; mutex_lock(&cbe_spu_info[node].list_mutex); cbe_spu_info[node].nr_active--; spu->alloc_state = SPU_FREE; spu_unbind_context(spu, ctx); ctx->stats.invol_ctx_switch++; spu->stats.invol_ctx_switch++; mutex_unlock(&cbe_spu_info[node].list_mutex); } /** * spu_activate - find a free spu for a context and execute it * @ctx: spu context to schedule * @flags: flags (currently ignored) * * Tries to find a free spu to run @ctx. If no free spu is available * add the context to the runqueue so it gets woken up once an spu * is available. */ int spu_activate(struct spu_context *ctx, unsigned long flags) { struct spu *spu; /* * If there are multiple threads waiting for a single context * only one actually binds the context while the others will * only be able to acquire the state_mutex once the context * already is in runnable state. */ if (ctx->spu) return 0; spu_activate_top: if (signal_pending(current)) return -ERESTARTSYS; spu = spu_get_idle(ctx); /* * If this is a realtime thread we try to get it running by * preempting a lower priority thread. */ if (!spu && rt_prio(ctx->prio)) spu = find_victim(ctx); if (spu) { unsigned long runcntl; runcntl = ctx->ops->runcntl_read(ctx); __spu_schedule(spu, ctx); if (runcntl & SPU_RUNCNTL_RUNNABLE) spuctx_switch_state(ctx, SPU_UTIL_USER); return 0; } if (ctx->flags & SPU_CREATE_NOSCHED) { spu_prio_wait(ctx); goto spu_activate_top; } spu_add_to_rq(ctx); return 0; } /** * grab_runnable_context - try to find a runnable context * * Remove the highest priority context on the runqueue and return it * to the caller. Returns %NULL if no runnable context was found. */ static struct spu_context *grab_runnable_context(int prio, int node) { struct spu_context *ctx; int best; spin_lock(&spu_prio->runq_lock); best = find_first_bit(spu_prio->bitmap, prio); while (best < prio) { struct list_head *rq = &spu_prio->runq[best]; list_for_each_entry(ctx, rq, rq) { /* XXX(hch): check for affinity here aswell */ if (__node_allowed(ctx, node)) { __spu_del_from_rq(ctx); goto found; } } best++; } ctx = NULL; found: spin_unlock(&spu_prio->runq_lock); return ctx; } static int __spu_deactivate(struct spu_context *ctx, int force, int max_prio) { struct spu *spu = ctx->spu; struct spu_context *new = NULL; if (spu) { new = grab_runnable_context(max_prio, spu->node); if (new || force) { spu_unschedule(spu, ctx); if (new) { if (new->flags & SPU_CREATE_NOSCHED) wake_up(&new->stop_wq); else { spu_release(ctx); spu_schedule(spu, new); /* this one can't easily be made interruptible */ mutex_lock(&ctx->state_mutex); } } } } return new != NULL; } /** * spu_deactivate - unbind a context from it's physical spu * @ctx: spu context to unbind * * Unbind @ctx from the physical spu it is running on and schedule * the highest priority context to run on the freed physical spu. */ void spu_deactivate(struct spu_context *ctx) { spu_context_nospu_trace(spu_deactivate__enter, ctx); __spu_deactivate(ctx, 1, MAX_PRIO); } /** * spu_yield - yield a physical spu if others are waiting * @ctx: spu context to yield * * Check if there is a higher priority context waiting and if yes * unbind @ctx from the physical spu and schedule the highest * priority context to run on the freed physical spu instead. */ void spu_yield(struct spu_context *ctx) { spu_context_nospu_trace(spu_yield__enter, ctx); if (!(ctx->flags & SPU_CREATE_NOSCHED)) { mutex_lock(&ctx->state_mutex); __spu_deactivate(ctx, 0, MAX_PRIO); mutex_unlock(&ctx->state_mutex); } } static noinline void spusched_tick(struct spu_context *ctx) { struct spu_context *new = NULL; struct spu *spu = NULL; if (spu_acquire(ctx)) BUG(); /* a kernel thread never has signals pending */ if (ctx->state != SPU_STATE_RUNNABLE) goto out; if (ctx->flags & SPU_CREATE_NOSCHED) goto out; if (ctx->policy == SCHED_FIFO) goto out; if (--ctx->time_slice && test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags)) goto out; spu = ctx->spu; spu_context_trace(spusched_tick__preempt, ctx, spu); new = grab_runnable_context(ctx->prio + 1, spu->node); if (new) { spu_unschedule(spu, ctx); if (test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags)) spu_add_to_rq(ctx); } else { spu_context_nospu_trace(spusched_tick__newslice, ctx); if (!ctx->time_slice) ctx->time_slice++; } out: spu_release(ctx); if (new) spu_schedule(spu, new); } /** * count_active_contexts - count nr of active tasks * * Return the number of tasks currently running or waiting to run. * * Note that we don't take runq_lock / list_mutex here. Reading * a single 32bit value is atomic on powerpc, and we don't care * about memory ordering issues here. */ static unsigned long count_active_contexts(void) { int nr_active = 0, node; for (node = 0; node < MAX_NUMNODES; node++) nr_active += cbe_spu_info[node].nr_active; nr_active += spu_prio->nr_waiting; return nr_active; } /** * spu_calc_load - update the avenrun load estimates. * * No locking against reading these values from userspace, as for * the CPU loadavg code. */ static void spu_calc_load(void) { unsigned long active_tasks; /* fixed-point */ active_tasks = count_active_contexts() * FIXED_1; CALC_LOAD(spu_avenrun[0], EXP_1, active_tasks); CALC_LOAD(spu_avenrun[1], EXP_5, active_tasks); CALC_LOAD(spu_avenrun[2], EXP_15, active_tasks); } static void spusched_wake(unsigned long data) { mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK); wake_up_process(spusched_task); } static void spuloadavg_wake(unsigned long data) { mod_timer(&spuloadavg_timer, jiffies + LOAD_FREQ); spu_calc_load(); } static int spusched_thread(void *unused) { struct spu *spu; int node; while (!kthread_should_stop()) { set_current_state(TASK_INTERRUPTIBLE); schedule(); for (node = 0; node < MAX_NUMNODES; node++) { struct mutex *mtx = &cbe_spu_info[node].list_mutex; mutex_lock(mtx); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) { struct spu_context *ctx = spu->ctx; if (ctx) { get_spu_context(ctx); mutex_unlock(mtx); spusched_tick(ctx); mutex_lock(mtx); put_spu_context(ctx); } } mutex_unlock(mtx); } } return 0; } void spuctx_switch_state(struct spu_context *ctx, enum spu_utilization_state new_state) { unsigned long long curtime; signed long long delta; struct timespec ts; struct spu *spu; enum spu_utilization_state old_state; int node; ktime_get_ts(&ts); curtime = timespec_to_ns(&ts); delta = curtime - ctx->stats.tstamp; WARN_ON(!mutex_is_locked(&ctx->state_mutex)); WARN_ON(delta < 0); spu = ctx->spu; old_state = ctx->stats.util_state; ctx->stats.util_state = new_state; ctx->stats.tstamp = curtime; /* * Update the physical SPU utilization statistics. */ if (spu) { ctx->stats.times[old_state] += delta; spu->stats.times[old_state] += delta; spu->stats.util_state = new_state; spu->stats.tstamp = curtime; node = spu->node; if (old_state == SPU_UTIL_USER) atomic_dec(&cbe_spu_info[node].busy_spus); if (new_state == SPU_UTIL_USER) atomic_inc(&cbe_spu_info[node].busy_spus); } } #define LOAD_INT(x) ((x) >> FSHIFT) #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100) static int show_spu_loadavg(struct seq_file *s, void *private) { int a, b, c; a = spu_avenrun[0] + (FIXED_1/200); b = spu_avenrun[1] + (FIXED_1/200); c = spu_avenrun[2] + (FIXED_1/200); /* * Note that last_pid doesn't really make much sense for the * SPU loadavg (it even seems very odd on the CPU side...), * but we include it here to have a 100% compatible interface. */ seq_printf(s, "%d.%02d %d.%02d %d.%02d %ld/%d %d\n", LOAD_INT(a), LOAD_FRAC(a), LOAD_INT(b), LOAD_FRAC(b), LOAD_INT(c), LOAD_FRAC(c), count_active_contexts(), atomic_read(&nr_spu_contexts), current->nsproxy->pid_ns->last_pid); return 0; } static int spu_loadavg_open(struct inode *inode, struct file *file) { return single_open(file, show_spu_loadavg, NULL); } static const struct file_operations spu_loadavg_fops = { .open = spu_loadavg_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; int __init spu_sched_init(void) { struct proc_dir_entry *entry; int err = -ENOMEM, i; spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL); if (!spu_prio) goto out; for (i = 0; i < MAX_PRIO; i++) { INIT_LIST_HEAD(&spu_prio->runq[i]); __clear_bit(i, spu_prio->bitmap); } spin_lock_init(&spu_prio->runq_lock); setup_timer(&spusched_timer, spusched_wake, 0); setup_timer(&spuloadavg_timer, spuloadavg_wake, 0); spusched_task = kthread_run(spusched_thread, NULL, "spusched"); if (IS_ERR(spusched_task)) { err = PTR_ERR(spusched_task); goto out_free_spu_prio; } mod_timer(&spuloadavg_timer, 0); entry = proc_create("spu_loadavg", 0, NULL, &spu_loadavg_fops); if (!entry) goto out_stop_kthread; pr_debug("spusched: tick: %d, min ticks: %d, default ticks: %d\n", SPUSCHED_TICK, MIN_SPU_TIMESLICE, DEF_SPU_TIMESLICE); return 0; out_stop_kthread: kthread_stop(spusched_task); out_free_spu_prio: kfree(spu_prio); out: return err; } void spu_sched_exit(void) { struct spu *spu; int node; remove_proc_entry("spu_loadavg", NULL); del_timer_sync(&spusched_timer); del_timer_sync(&spuloadavg_timer); kthread_stop(spusched_task); for (node = 0; node < MAX_NUMNODES; node++) { mutex_lock(&cbe_spu_info[node].list_mutex); list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) if (spu->alloc_state != SPU_FREE) spu->alloc_state = SPU_FREE; mutex_unlock(&cbe_spu_info[node].list_mutex); } kfree(spu_prio); }