Sub-blocking vs cache-line-overwrite (Was Re: RE: RE: [gclist] reference counting)

Manoj Plakal
Fri, 15 Sep 2000 00:56:53 -0500

Jeff Sturm wrote (Fri, Sep 15, 2000 at 01:37:28AM -0400) :
> I'm not really familiar with this capability.  On the other hand,
> write-allocate seems to be available with Alpha EV6, and I think I heard
> someone say MIPS and PA-RISC have it too.

	I think "write-allocate" means that a write miss will allocate 
	a block in the cache AND fill it with previous contents, as
	opposed to a write-noallocate which bypasses the cache
	on a write miss (straight from Hennessy & Patterson, Chap 5).

	The term we should use is something like "write-allocate-nofill",
	a write miss will allocate a line but NOT fill it from memory.
	Which is what the WH64 Alpha instruction does (as a hint).