Messages in this thread | | | Date | Fri, 08 Aug 2008 21:44:31 +0200 | From | Stefan Richter <> | Subject | Scatter-gather segment merges by IOMMU? |
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Hi all,
the block layer usually tries to merge s/g segments if consecutive segments combined fit into the queue's max_segment_size. When such a scatter gather list is DMA-mapped, can it happen that an IOMMU collapses the elements even further, so that sg_dma_len() of a DMA-mapped s/g segment exceeds max_segment_size?
As I understood some discussions in the past, this could indeed happen, which is a nuisance. But I may have misunderstood something, or something may have changed in the meantime... -- Stefan Richter -=====-==--- =--- -=--- http://arcgraph.de/sr/
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