On Wed, Nov 30, 2005 at 12:45:27PM -0600, James Bottomley wrote: > On Wed, 2005-11-30 at 10:36 -0800, Mark Haverkamp wrote: > > This patch changes map_single to map_page in compliance with > > recommendations made in the IO-Perf howto document to prevent bounce > > buffering of DMA requests. > > Erm, there's a misunderstanding somewhere. You're replacing correct > pci_map_single calls with its more difficult to use pci_map_page. This > has absolutely zero performance impact and adds the risk that because > pci_map_page is more complex to use, someone gets it wrong somewhere. > Really, for block devices pci_map_single is the absolutely correct > interface. pci_map_page should really only be used by the net stack for > packet fragment mapping. And the really nice thing is that this whole non-S/G I/O path will go away completely for 2.6.16 :) - : 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
