[PATCH 2/3] native hash clear

[Paul Mackerras]

R Sharada writes:

> Add code to clear the hash table and invalidate the tlb for native (SMP,
> non-LPAR) mode.  Supports 16M and 4k pages.

> +	/* we take the tlbie lock and hold it.  Some hardware will
> +	 * deadlock if we try to tlbie from two processors at once.
> +	 */
> +	spin_lock(&native_tlbie_lock);
...
> +		/*
> +		 * we could lock the pte here, but we are the only cpu
> +		 * running,  right?  and for crash dump, we probably
> +		 * don't want to wait for a maybe bad cpu.
> +		 */

So which is it?  Are we locking things, and possibly waiting forever
for a bad cpu, or are we not locking things?  Or is there a reason why
we lock in one case but not the other?

Paul.