Re: [PATCH v4 8/17] iommufd: Algorithms for PFN storage

On Mon, Nov 07, 2022 at 08:49:01PM -0400, Jason Gunthorpe wrote:

+/*

• • Each interval represents an active iopt_access_pages(), it acts as an
• • interval lock that keeps the PFNs pinned and stored in the xarray.
• */

+struct iopt_pages_access {

• struct interval_tree_node node;
• refcount_t refcount;

I noticed this is never used unlocked, everything holds the pages->mutex for the pages that holds the node in its itree

So this is just an unsigned int, we don't need that atomic.

Jason