[POWERPC] spu sched: ensure preempted threads are put back on the runqueue

To not lose a spu thread we need to make sure it always gets put back
on the runqueue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 003e330fc76f..5149dff65c9e 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -97,7 +97,7 @@ void spu_sched_tick(struct work_struct *work)
         struct spu_context *ctx =
                 container_of(work, struct spu_context, sched_work.work);
         struct spu *spu;
-        int rearm = 1;
+        int preempted = 0;
 
         /*
          * If this context is being stopped avoid rescheduling from the
@@ -113,12 +113,19 @@ void spu_sched_tick(struct work_struct *work)
                 int best = sched_find_first_bit(spu_prio->bitmap);
                 if (best <= ctx->prio) {
                         spu_deactivate(ctx);
-                        rearm = 0;
+                        preempted = 1;
                 }
         }
         mutex_unlock(&ctx->state_mutex);
 
-        if (rearm)
+        if (preempted) {
+                /*
+                 * We need to break out of the wait loop in spu_run manually
+                 * to ensure this context gets put on the runqueue again
+                 * ASAP.
+                 */
+                wake_up(&ctx->stop_wq);
+        } else
                 spu_start_tick(ctx);
 }