powerpc/spufs: Fix possible scheduling of a context to multiple SPEs
We currently have a race when scheduling a context to a SPE -
after we have found a runnable context in spusched_tick, the same
context may have been scheduled by spu_activate().
This may result in a panic if we try to unschedule a context that has
been freed in the meantime.
This change exits spu_schedule() if the context has already been
scheduled, so we don't end up scheduling it twice.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 897c740..67595bc 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -728,7 +728,8 @@
/* 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);
+ if (ctx->state == SPU_STATE_SAVED)
+ __spu_schedule(spu, ctx);
spu_release(ctx);
}
