Messages in this thread | | | Date | Wed, 13 Dec 2006 09:38:26 +0100 | From | "Franck Bui-Huu" <> | Subject | Re: [RFC 2.6.19 1/1] fbdev,mm: hecuba/E-Ink fbdev driver v2 |
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On 12/12/06, Jaya Kumar <jayakumar.lkml@gmail.com> wrote: > I think that PTEs set up by vmalloc are marked cacheable and via the > above nopage end up as cacheable. I'm not doing DMA. So the accesses > are through the cache so I don't think cache aliasing is an issue for > this case. Please let me know if I misunderstood. >
This issue is not related to DMA: there are 2 different virtual addresses that can map the same physical address. If these 2 virtual addresses use 2 different data cache entries then you have a cache aliasing issue. In your case the 2 different virtual addresses are (1) the one got by the kernel (returned by vmalloc) (2) the one got by the application (returned by mmap).
Hope that helps. -- Franck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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