On Tue, Dec 09, 2008 at 12:56:27PM -0800, Jason Thorpe wrote:
On Dec 9, 2008, at 12:23 PM, Manuel Bouyer wrote:
Sure. And you don't care much about command completion either, as
long as the write to disk happen in order.
And the only way to ensure that is using FUA (or explicit cache
flushing).
But to enforce that using FUA, you have to set FUA on *every* write.
And I do not understand the "only way" in your remark above. Under
the constraint "if WCE is set in the cache control page" I agree that
it is correct. But as far as I can tell, if WCE is *not* set, it is
not in fact the case that using FUA is the "only way" to ensure that
writes are committed to stable storage in order -- because the tag
ordering rules require ordered tags to complete, um, well, in-order,
and if WCE is not set, commands are not supposed to complete until
the bits are on oxide.
I am sure I am misunderstanding something. What?