Messages in this thread | | | Subject | Re: Cache coherency and snooping | From | Alan Cox <> | Date | 14 Aug 2002 00:38:08 +0100 |
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On Wed, 2002-08-14 at 00:22, Imran Badr wrote: > How can I define a certain region of memory so that it is never cached? I > want to use non-cached region of memory to communicate to my PCI device to > avoid system overhead in cache snooping.
Architecture specific and for RAM quite often not supported at all. You can use ioremap_nocache on ram in theory but that doesn't actually work on most processors, will MCE on the PPro and needs some work on Athlon XP/MP
K6/K5 don't support it at all from memory.
If your hardware is sane it will already be doing cache line size bursts and MWI.
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