Subject: Re: [PATCH] powerpc/8xx: reduce pressure on TLB due to context switches

From: Scott Wood <[email-masked]>
Date: Tue, 6 Jan 2015 20:52:46 -0600

On Mon, 2015-01-05 at 16:14 +0100, Christophe Leroy wrote:
> +		}
> +		__clear_bit(id, stale_map[cpu]);
> +
> +	}

Whitespace

> +
> +	/* Flush the TLB for all contexts */
> +	_tlbil_all();

Can you put a comment in here pointing out that for this to work on SMP,
it needs to be a global invalidation, or at least some indication on
this function that it's not SMP-safe?  I realize there's no SMP 8xx, and
this is only called in place of steal_context_up(), but in case others
think of reusing this elsewhere[1]...

-Scott

[1] It might be helpful on e500 derivatives in virtualized environments
where invalidate-by-PID is expensive, depending on how often stealing
happens there.