Messages in this thread | | | Subject | Re: DMA transfers in 2.5.67 | From | (Måns Rullgård) | Date | 15 Apr 2003 23:38:14 +0200 |
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Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
> > What do I need to do in a driver before doing DMA transfers to a PCI > > card? Using a driver that worked in 2.4 gives a throughput of only 10 > > MB/s in 2.5.67. Is there some magic initialization that I have > > missed? > > Assuming your driver uses the new PCI api for DMA in 2.4/2.5 then there > isnt really anything to watch. Is this on a box with > 800Mb of memory > however ?
It's an Alpha with 768 MB. Is it the pci_alloc_* functions you are referring to? I don't think they are used currently. How much memory can these allocate? I need chunks of up to 1 MB, not necessarily phycically continuous.
What do those functions do that normal memory allocation does not? Apart from setting up sg mappings, that is.
-- Måns Rullgård mru@users.sf.net - 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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