On Wed, 27 Aug 2008 16:14:24 -0400 Douglas Gilbert <dougg@xxxxxxxxxx> wrote: > FUJITA Tomonori wrote: > > This patchset converts sg to use the block layer functions. That is, > > sg doesn't use scsi_execute_async() any more. This is a part of the > > overdue task to remove scsi_req_map_sg. > > > > I tested this patchset with sg v3 and the old interface (struct > > sg_header) via SG_IO (v3) and the vfs API. > > > > > > Doug, > > > > 1. I don't demote the sg driver's GFP_ATOMIC to GFP_KERNEL. sg always > > uses GFP_ATOMIC as before. > > > > 2. I don't remove GFP_DMA allocation. As before, sg allocates reserved > > pages with GFP_DMA (sfp->low_dma case). > > > > 3. I keep the reserved buffer per struct sg_fd as before. > > > > 4. I use high-order page allocation for reserved buffer as before. sg > > works well with HBAs that have the limitation of the number of sg > > entries. > > > > 5. I think that you were concern about the overhead of the block layer > > functions. But if you look at scsi_execute_async() that sg uses now, > > you can find that scsi_execute_async() uses the block layer functions > > internally. So the current sg incurs the overhead (if such overhead > > exists). > > Tomo, > Thanks for doing the conversion. > > Signed-off-by: Douglas Gilbert <dougg@xxxxxxxxxx> Thanks a lot! -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
