Introduce the function pmap_enter_object(). It maps a sequence of resident

pages from the same object.  Use it in vm_map_pmap_enter() to reduce the
locking overhead of premapping objects.

Reviewed by: tegge@

1 files changed, 28 insertions, 1 deletions

diff --git a/sys/arm/arm/pmap.c b/sys/arm/arm/pmap.c
index 45adf51..25c66cd 100644
--- a/sys/arm/arm/pmap.c
+++ b/sys/arm/arm/pmap.c
@@ -3579,6 +3579,34 @@ pmap_enter_locked(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
 }
 
 /*
+ * Maps a sequence of resident pages belonging to the same object.
+ * The sequence begins with the given page m_start.  This page is
+ * mapped at the given virtual address start.  Each subsequent page is
+ * mapped at a virtual address that is offset from start by the same
+ * amount as the page is offset from m_start within the object.  The
+ * last page in the sequence is the page with the largest offset from
+ * m_start that can be mapped at a virtual address less than the given
+ * virtual address end.  Not every virtual page between start and end
+ * is mapped; only those for which a resident page exists with the
+ * corresponding offset from m_start are mapped.
+ */
+void
+pmap_enter_object(pmap_t pmap, vm_offset_t start, vm_offset_t end,
+    vm_page_t m_start, vm_prot_t prot)
+{
+	vm_page_t m;
+	vm_pindex_t diff, psize;
+
+	psize = atop(end - start);
+	m = m_start;
+	while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) {
+		pmap_enter_locked(pmap, start + ptoa(diff), m, prot &
+		    (VM_PROT_READ | VM_PROT_EXECUTE), FALSE);
+		m = TAILQ_NEXT(m, listq);
+	}
+}
+
+/*
  * this code makes some *MAJOR* assumptions:
  * 1. Current pmap & pmap exists.
  * 2. Not wired.
@@ -3592,7 +3620,6 @@ pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
     vm_page_t mpte)
 {
 
-	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
 	pmap_enter_locked(pmap, va, m, prot & (VM_PROT_READ | VM_PROT_EXECUTE),
 	    FALSE);
 	return (NULL);