21 Dec
2021
21 Dec
'21
6:58 p.m.
On Tue, Dec 21, 2021 at 10:51 AM David Hildenbrand david@redhat.com wrote:
For that purpose the pincount would already kind-off work. Not precise, but at least something ("this page cannot possibly have been pinned").
That part actually exists already, ie put_page_refs() has this:
#ifdef CONFIG_DEBUG_VM if (VM_WARN_ON_ONCE_PAGE(page_ref_count(page) < refs, page)) return; #endif
And yeah, it shouldn't have that '#ifdef CONFIG_DEBUG_VM' there, but I think it's because the non-CONFIG_DEBUG_VM #define for VM_WARN_ON_ONCE_PAGE() is broken, and doesn't return 0.
Linus