On 26.04.24 05:43, Pasha Tatashin wrote:
Changelog
================================================================
v2: Use mapcount instead of refcount
Synchronized with IOMMU Observability changes.
================================================================
This series frees empty page tables on unmaps. It intends to be a
low overhead feature.
The read-writer lock is used to synchronize page table, but most of
time the lock is held is reader. It is held as a writer for short
period of time when unmapping a page that is bigger than the current
iova request. For all other cases this lock is read-only.
page->mapcount is used in order to track number of entries at each page
table.
I'm wondering if this will conflict with page_type at some point? We're
already converting other page table users to ptdesc. CCing Willy.
--
Cheers,
David / dhildenb
