On 27/04/17 05:20 PM, Jason Gunthorpe wrote: > It seems the most robust: test for iomem, and jump to a slow path > copy, otherwise inline the kmap and memcpy > > Every place doing memcpy from sgl will need that pattern to be > correct.
Ok, sounds like a good place to start to me. I'll see what I can do for a v3 of this set. Though, I probably won't send anything until after the merge window. >>> sg_miter will still fail when the sg contains __iomem, however I would >>> expect that the sg_copy will work with iomem, by using the __iomem >>> memcpy variant. >> >> Yes, that's true. Any sg_miters that ever see iomem will need to be >> converted to support it. This isn't much different than the other >> kmap(sg_page()) users I was converting that will also fail if they see >> iomem. Though, I suspect an sg_miter user would be easier to convert to >> iomem than a random kmap user. > > How? sg_miter seems like the next nightmare down this path, what is > sg_miter_next supposed to do when something hits an iomem sgl? My proposal is roughly included in the draft I sent upthread. We add an sg_miter flag indicating the iteratee supports iomem and if miter finds iomem (with the support flag set) it sets ioaddr which is __iomem. The iteratee then just needs to null check addr and ioaddr and perform the appropriate action. Logan -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.