[POWERPC] spufs: fix invalid scheduling of forgotten contexts
At present, we have a situation where a context with no owner is
re-scheduled by spu_forget:
Thread 1: reading regs file Thread 2: context owner
spu_forget()
- ctx->owner = NULL
- set SPU_SCHED_WAS_ACTIVE
spu_acquire_saved()
- context is in saved state
spu_release_saved()
- SPU_SCHED_WAS_ACTIVE is set,
so spu_activate() the context,
which now has no owner
In spu_forget(), we shouldn't be requesting a re-schedule by setting
SPU_SCHED_WAS_ACTIVE. This change removes the set_bit in spu_forget(),
so that spu_release_saved() doesn't reinsert this destroyed context on
to the run queue.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index 133995e..cf6c2c8 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -109,13 +109,12 @@
/*
* This is basically an open-coded spu_acquire_saved, except that
- * we don't acquire the state mutex interruptible.
+ * we don't acquire the state mutex interruptible, and we don't
+ * want this context to be rescheduled on release.
*/
mutex_lock(&ctx->state_mutex);
- if (ctx->state != SPU_STATE_SAVED) {
- set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags);
+ if (ctx->state != SPU_STATE_SAVED)
spu_deactivate(ctx);
- }
mm = ctx->owner;
ctx->owner = NULL;