On 5/2/21 4:28 PM, John Hubbard wrote:

On 4/8/21 10:01 AM, Logan Gunthorpe wrote:

...

quoted

@@ -387,19 +388,37 @@ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,

This routine now deserves a little bit of commenting, now that it is
doing less obvious things. How about something like this:

/*
* Unmaps pages, except for PCI_P2PDMA pages, which were never mapped in the
* first place. Instead of unmapping PCI_P2PDMA entries, simply remove the
* SG_PCI_P2PDMA mark
*/

I got that kind of wrong. They *were* mapped, but need to be left mostly
alone...maybe you can word it better. Here's my second draft:

/*
  * Unmaps pages, except for PCI_P2PDMA pages, which should not be unmapped at
  * this point. Instead of unmapping PCI_P2PDMA entries, simply remove the
  * SG_PCI_P2PDMA mark.
  */

...am I getting close? :)

thanks,
-- 
John Hubbard
NVIDIA