Messages in this thread | | | Date | Wed, 4 Jun 2008 12:47:14 +0100 | From | Alan Cox <> | Subject | Re: MMIO and gcc re-ordering issue |
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> Anyway, Intel certainly seems to document that WC memory is serialized by > any access to UC memory.
I don't believe that is actually true on Pentium Pro at least.
> So what started out as a "we can do accesses to the frame buffer more > efficiently without anybody ever even having to know or care" has > turned into a whole nightmare of people using it for other things, and > then you very much _do_ have to care! ]
Notably graphics where 3Dfx lined the registers up specifically to make this work. We were also using it with I²O where it gave a small performance gain.
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