Messages in this thread | | | Date | Wed, 22 Aug 2007 09:39:36 +0200 | From | Jes Sorensen <> | Subject | Re: [PATCH 2/3] dma: override "dma_flags_set_dmaflush" for sn-ia64 |
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James Bottomley wrote: > On Tue, 2007-08-21 at 17:34 -0700, akepner@sgi.com wrote: >> The term "posted DMA" is used to describe this behavior in the Altix >> Device Driver Writer's Guide, but it may be confusing things here. >> Maybe a better term will suggest itself if I can clarify.... > > OK, but posted DMA has a pretty specific meaning in terms of PCI, hence > the confusion.
Maybe it would be more better to refer to this as 'out of order DMA'?
>> On Altix, DMA from a device isn't guaranteed to arrive in host memory >> in the order it was sent from the device. This reordering can happen >> in the NUMA interconnect (it's specifically not a PCI reordering.) > > This is mmiowb and read_relaxed() again, isn't it?
I believe it's the same problem, except this time it's when exposing structures to userland.
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