On Sun, Mar 18, 2012 at 10:06:10PM +0000, Al Viro wrote:

On Sun, Mar 18, 2012 at 03:01:08PM -0700, Linus Torvalds wrote:

quoted

On Sun, Mar 18, 2012 at 12:07 PM, Al Viro [off-list ref] wrote:

quoted

- ? ? ? tlb_finish_mmu(&tlb, 0, end);
+ ? ? ? tlb_finish_mmu(&tlb, 0, -1);

Hmm. The fact that you drop the end pointer means that some
architectures that optimize the TLB flushing for ranges now
effectively can't do it any more.

Now, I think it's only ia64 that really is affected, but it *might* matter.

In particular, ia64 has some logic for "if you only flush one single
region, you can optimize it", and the region sizes are in the
terabytes. And I'm pretty sure you broke that - I'm just not entirely
sure how much we care.

Nope - ia64 check explicitly for precisely that case:

[snip]
... and everything else doesn't look at start or end at all.

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