Re: [PATCH 1/2] Enable SPU switch notification to detect currently active SPU tasks.

On Fri, Jul 13, 2007 at 10:34:50PM +1000, Benjamin Herrenschmidt wrote:

quoted

quoted

+		if (unlikely(test_bit(SPU_SCHED_NOTIFY_ACTIVE,
+				      &ctx->sched_flags))) {
+			clear_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags);

this should use test_and_clear_bit

This also looks like an abuse of atomics to effectively implement a lock
or did I miss something ?

not really.  We set a flag on the context to make sure some action is
performed when it comes through spu_run the next time.  It's not exactly
elegant, but cleaning this up will have to wait for the grand spu_run
rewrite.