* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-#define DEBUG 1
-#include <linux/config.h>
+#undef DEBUG
+
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <asm/mmu_context.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
+#include <asm/spu_priv1.h>
#include "spufs.h"
+#define SPU_MIN_TIMESLICE (100 * HZ / 1000)
+
#define SPU_BITMAP_SIZE (((MAX_PRIO+BITS_PER_LONG)/BITS_PER_LONG)+1)
struct spu_prio_array {
atomic_t nr_blocked;
}
}
-static void prio_wait(struct spu_runqueue *rq, u64 flags)
+static void prio_wait(struct spu_runqueue *rq, struct spu_context *ctx,
+ u64 flags)
{
int prio = current->prio;
wait_queue_head_t *wq = &rq->prio.waitq[prio];
prepare_to_wait_exclusive(wq, &wait, TASK_INTERRUPTIBLE);
if (!signal_pending(current)) {
up(&rq->sem);
+ up_write(&ctx->state_sema);
pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__,
current->pid, current->prio);
schedule();
+ down_write(&ctx->state_sema);
down(&rq->sem);
}
finish_wait(wq, &wait);
spu->number);
spu->ctx = ctx;
spu->flags = 0;
+ ctx->flags = 0;
ctx->spu = spu;
ctx->ops = &spu_hw_ops;
spu->pid = current->pid;
mm_needs_global_tlbie(spu->mm);
spu->ibox_callback = spufs_ibox_callback;
spu->wbox_callback = spufs_wbox_callback;
+ spu->stop_callback = spufs_stop_callback;
+ spu->mfc_callback = spufs_mfc_callback;
mb();
+ spu_unmap_mappings(ctx);
spu_restore(&ctx->csa, spu);
+ spu->timestamp = jiffies;
}
static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
{
pr_debug("%s: unbind pid=%d SPU=%d\n", __FUNCTION__,
spu->pid, spu->number);
+ spu_unmap_mappings(ctx);
spu_save(&ctx->csa, spu);
+ 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->mm = NULL;
spu->pid = 0;
spu->prio = MAX_PRIO;
ctx->ops = &spu_backing_ops;
ctx->spu = NULL;
+ ctx->flags = 0;
+ spu->flags = 0;
spu->ctx = NULL;
}
-static struct spu *preempt_active(struct spu_runqueue *rq)
+static void spu_reaper(void *data)
{
- struct list_head *p;
- struct spu_context *ctx;
+ struct spu_context *ctx = data;
struct spu *spu;
- /* Future: implement real preemption. For now just
- * boot a lower priority ctx that is in "detached"
- * state, i.e. on a processor but not currently in
- * spu_run().
- */
+ down_write(&ctx->state_sema);
+ spu = ctx->spu;
+ if (spu && test_bit(SPU_CONTEXT_PREEMPT, &ctx->flags)) {
+ if (atomic_read(&spu->rq->prio.nr_blocked)) {
+ pr_debug("%s: spu=%d\n", __func__, spu->number);
+ ctx->ops->runcntl_stop(ctx);
+ spu_deactivate(ctx);
+ wake_up_all(&ctx->stop_wq);
+ } else {
+ clear_bit(SPU_CONTEXT_PREEMPT, &ctx->flags);
+ }
+ }
+ up_write(&ctx->state_sema);
+ put_spu_context(ctx);
+}
+
+static void schedule_spu_reaper(struct spu_runqueue *rq, struct spu *spu)
+{
+ struct spu_context *ctx = get_spu_context(spu->ctx);
+ unsigned long now = jiffies;
+ unsigned long expire = spu->timestamp + SPU_MIN_TIMESLICE;
+
+ set_bit(SPU_CONTEXT_PREEMPT, &ctx->flags);
+ INIT_WORK(&ctx->reap_work, spu_reaper, ctx);
+ if (time_after(now, expire))
+ schedule_work(&ctx->reap_work);
+ else
+ schedule_delayed_work(&ctx->reap_work, expire - now);
+}
+
+static void check_preempt_active(struct spu_runqueue *rq)
+{
+ struct list_head *p;
+ struct spu *worst = NULL;
+
list_for_each(p, &rq->active_list) {
- spu = list_entry(p, struct spu, sched_list);
- if (current->prio < spu->prio) {
- ctx = spu->ctx;
- if (down_write_trylock(&ctx->state_sema)) {
- if (ctx->state != SPU_STATE_RUNNABLE) {
- up_write(&ctx->state_sema);
- continue;
- }
- pr_debug("%s: booting pid=%d from SPU %d\n",
- __FUNCTION__, spu->pid, spu->number);
- del_active(rq, spu);
- up(&rq->sem);
- unbind_context(spu, ctx);
- up_write(&ctx->state_sema);
- return spu;
+ struct spu *spu = list_entry(p, struct spu, sched_list);
+ struct spu_context *ctx = spu->ctx;
+ if (!test_bit(SPU_CONTEXT_PREEMPT, &ctx->flags)) {
+ if (!worst || (spu->prio > worst->prio)) {
+ worst = spu;
}
}
}
- return NULL;
+ if (worst && (current->prio < worst->prio))
+ schedule_spu_reaper(rq, worst);
}
-static struct spu *get_idle_spu(u64 flags)
+static struct spu *get_idle_spu(struct spu_context *ctx, u64 flags)
{
struct spu_runqueue *rq;
struct spu *spu = NULL;
continue;
}
} else {
- if (is_best_prio(rq)) {
- if ((spu = preempt_active(rq)) != NULL)
- return spu;
- }
- prio_wait(rq, flags);
+ check_preempt_active(rq);
+ prio_wait(rq, ctx, flags);
if (signal_pending(current)) {
prio_wakeup(rq);
spu = NULL;
if (ctx->spu)
return 0;
- spu = get_idle_spu(flags);
+ spu = get_idle_spu(ctx, flags);
if (!spu)
return (signal_pending(current)) ? -ERESTARTSYS : -EAGAIN;
bind_context(spu, ctx);
+ /*
+ * We're likely to wait for interrupts on the same
+ * CPU that we are now on, so send them here.
+ */
+ spu_cpu_affinity_set(spu, raw_smp_processor_id());
put_active_spu(spu);
return 0;
}
void spu_yield(struct spu_context *ctx)
{
struct spu *spu;
+ int need_yield = 0;
- if (!down_write_trylock(&ctx->state_sema))
- return;
+ down_write(&ctx->state_sema);
spu = ctx->spu;
- if ((ctx->state == SPU_STATE_RUNNABLE) &&
- (sched_find_first_bit(spu->rq->prio.bitmap) <= current->prio)) {
+ if (spu && (sched_find_first_bit(spu->rq->prio.bitmap) < MAX_PRIO)) {
pr_debug("%s: yielding SPU %d\n", __FUNCTION__, spu->number);
spu_deactivate(ctx);
ctx->state = SPU_STATE_SAVED;
+ need_yield = 1;
+ } else if (spu) {
+ spu->prio = MAX_PRIO;
}
up_write(&ctx->state_sema);
+ if (unlikely(need_yield))
+ yield();
}
int __init spu_sched_init(void)
pr_debug("%s: adding SPU[%d]\n", __FUNCTION__, spu->number);
add_idle(rq, spu);
spu->rq = rq;
+ spu->timestamp = jiffies;
}
if (!rq->nr_idle) {
printk(KERN_WARNING "%s: No available SPUs.\n", __FUNCTION__);
projects / linux-2.6 / blobdiff