Re: [PATCH 6/24] make atomic_read() behave consistently on frv

[Chris Snook]

Chris Snook wrote:
> From: Chris Snook <csnook@xxxxxxxxxx>
>
> Make atomic_read() volatile on frv.  This ensures that busy-waiting
> for an interrupt handler to change an atomic_t won't get compiled to an
> infinite loop, consistent with SMP architectures.

To head off the criticism, I admit this is an oversimplification, and true 
busy-waiters should be using cpu_relax(), which contains a barrier.  As 
discussed in recent threads, there are other cases which can be optimized by 
removing the need for a barrier, and having behavior consistent with 
architectures where the benefit is more profound is also valuable.

	-- Chris
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/