[POWERPC] spusched: Update scheduling paramters on every spu_run

Update scheduling information on every spu_run to allow for setting
threads to realtime priority just before running them.  This requires
some slightly ugly code in spufs_run_spu because we can just update
the information unlocked if the spu is not runnable, but we need to
acquire the active_mutex when it is runnable to protect against
find_victim.  This locking scheme requires opencoding
spu_acquire_runnable in spufs_run_spu which actually is a nice cleanup
all by itself.

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

1 files changed, 16 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 89b02b6bfc55..4e0db6ae0d5e 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -301,9 +301,22 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx,
         ctx->ops->master_start(ctx);
         ctx->event_return = 0;
 
-        ret = spu_acquire_runnable(ctx, 0);
-        if (ret)
-                return ret;
+        spu_acquire(ctx);
+        if (ctx->state == SPU_STATE_SAVED) {
+                __spu_update_sched_info(ctx);
+
+                ret = spu_activate(ctx, 0);
+                if (ret) {
+                        spu_release(ctx);
+                        goto out;
+                }
+        } else {
+                /*
+                 * We have to update the scheduling priority under active_mutex
+                 * to protect against find_victim().
+                 */
+                spu_update_sched_info(ctx);
+        }
 
         ret = spu_run_init(ctx, npc);
         if (ret) {