Jeff, We had a discussion here today about IOMMUs, and they *never* split sg list entries -- they only ever *merge*. And this happens only after the block layer has already done merging while respecting q->seg_boundary_mask. So worst case, the IOMMU may merge everything, and then in libata we unmerge them again. But the end result can never exceed the max_sg_entries limit enforced by the block layer. So.. why are we still specifying .sg_tablesize as half of what the LLD can really handle? This can cost a lot of memory, as using NCQ effectively multiplies everything by 32.. Based on this information, I should be able to do this in sata_mv, for example: - .sg_tablesize = MV_MAX_SG_CT / 2, + .sg_tablesize = MV_MAX_SG_CT, ??? - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
