svn commit: r326055 - head/sys/vm

[Mark Johnston]

Author: markj
Date: Tue Nov 21 13:17:40 2017
New Revision: 326055
URL: https://svnweb.freebsd.org/changeset/base/326055

Log:
  Allow for fictitious physical pages in vm_page_scan_contig().
  
  Some drm2 drivers will set PG_FICTITIOUS in physical pages in order to
  satisfy the OBJT_MGTDEVICE object interface, so a scan may encounter
  fictitous pages. For now, allow for this possibility; such pages will be
  skipped later in the scan since they are wired.
  
  Reported by:	avg
  Reviewed by:	kib
  MFC after:	1 week

Modified:
  head/sys/vm/vm_page.c

Modified: head/sys/vm/vm_page.c
==============================================================================
--- head/sys/vm/vm_page.c	Tue Nov 21 10:19:33 2017	(r326054)
+++ head/sys/vm/vm_page.c	Tue Nov 21 13:17:40 2017	(r326055)
@@ -2065,8 +2065,10 @@ vm_page_scan_contig(u_long npages, vm_page_t m_start, 
 	run_len = 0;
 	m_mtx = NULL;
 	for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
-		KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
-		    ("page %p is PG_FICTITIOUS or PG_MARKER", m));
+		KASSERT((m->flags & PG_MARKER) == 0,
+		    ("page %p is PG_MARKER", m));
+		KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->wire_count == 1,
+		    ("fictitious page %p has invalid wire count", m));
 
 		/*
 		 * If the current page would be the start of a run, check its