Re: [PATCH] speed up SATA

Jeff Garzik
2004-03-27T23:40:47Z

Jeff Garzik wrote:
> That's the main limitation on request size right now... libata limits
> S/G table entries to 128[1], so a perfectly aligned, fully merged

...

[1] because even though the block layer properly splits on segment
boundaries, pci_map_sg() may violate those boundaries (James B and
others are working on fixing this). So... for right now the driver
must check the s/g entry boundaries after DMA mapping, and split them
(again) if necessary. IDE does this in ide_build_dmatable().