svn commit: r237404 - head/sys/amd64/amd64

[Alan Cox]

Author: alc
Date: Thu Jun 21 16:37:36 2012
New Revision: 237404
URL: http://svn.freebsd.org/changeset/base/237404

Log:
  Update the PV stats in free_pv_entry() using atomics.  After which, it is
  no longer necessary for free_pv_entry() to be serialized by the pvh global
  lock.
  
  Retire pmap_insert_entry() and pmap_remove_entry().  Once upon a time,
  these functions were called from multiple places within the pmap.  Now,
  each has only one caller.

Modified:
  head/sys/amd64/amd64/pmap.c

Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c	Thu Jun 21 16:21:31 2012	(r237403)
+++ head/sys/amd64/amd64/pmap.c	Thu Jun 21 16:37:36 2012	(r237404)
@@ -275,9 +275,6 @@ static int pmap_remove_pte(pmap_t pmap, 
 static void pmap_remove_pt_page(pmap_t pmap, vm_page_t mpte);
 static void pmap_remove_page(pmap_t pmap, vm_offset_t va, pd_entry_t *pde,
     vm_page_t *free);
-static void pmap_remove_entry(struct pmap *pmap, vm_page_t m,
-		vm_offset_t va);
-static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m);
 static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
     vm_page_t m, struct rwlock **lockp);
 static void pmap_update_pde(pmap_t pmap, vm_offset_t va, pd_entry_t *pde,
@@ -2207,10 +2204,10 @@ free_pv_entry(pmap_t pmap, pv_entry_t pv
 	struct pv_chunk *pc;
 	int idx, field, bit;
 
-	rw_assert(&pvh_global_lock, RA_WLOCKED);
+	rw_assert(&pvh_global_lock, RA_LOCKED);
 	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
-	PV_STAT(pv_entry_frees++);
-	PV_STAT(pv_entry_spare++);
+	PV_STAT(atomic_add_long(&pv_entry_frees, 1));
+	PV_STAT(atomic_add_int(&pv_entry_spare, 1));
 	PV_STAT(atomic_subtract_long(&pv_entry_count, 1));
 	pc = pv_to_chunk(pv);
 	idx = pv - &pc->pc_pventry[0];
@@ -2372,7 +2369,9 @@ pmap_pv_demote_pde(pmap_t pmap, vm_offse
 		KASSERT((m->oflags & VPO_UNMANAGED) == 0,
 		    ("pmap_pv_demote_pde: page %p is not managed", m));
 		va += PAGE_SIZE;
-		pmap_insert_entry(pmap, va, m);
+		pv = get_pv_entry(pmap, FALSE);
+		pv->pv_va = va;
+		TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
 	} while (va < va_last);
 }
 
@@ -2430,36 +2429,6 @@ pmap_pvh_free(struct md_page *pvh, pmap_
 	free_pv_entry(pmap, pv);
 }
 
-static void
-pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
-{
-	struct md_page *pvh;
-
-	rw_assert(&pvh_global_lock, RA_WLOCKED);
-	pmap_pvh_free(&m->md, pmap, va);
-	if (TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) {
-		pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
-		if (TAILQ_EMPTY(&pvh->pv_list))
-			vm_page_aflag_clear(m, PGA_WRITEABLE);
-	}
-}
-
-/*
- * Create a pv entry for page at pa for
- * (pmap, va).
- */
-static void
-pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
-{
-	pv_entry_t pv;
-
-	rw_assert(&pvh_global_lock, RA_WLOCKED);
-	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
-	pv = get_pv_entry(pmap, FALSE);
-	pv->pv_va = va;
-	TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
-}
-
 /*
  * Conditionally create a pv entry.
  */
@@ -2711,6 +2680,7 @@ static int
 pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, 
     pd_entry_t ptepde, vm_page_t *free)
 {
+	struct md_page *pvh;
 	pt_entry_t oldpte;
 	vm_page_t m;
 
@@ -2725,7 +2695,13 @@ pmap_remove_pte(pmap_t pmap, pt_entry_t 
 			vm_page_dirty(m);
 		if (oldpte & PG_A)
 			vm_page_aflag_set(m, PGA_REFERENCED);
-		pmap_remove_entry(pmap, m, va);
+		pmap_pvh_free(&m->md, pmap, va);
+		if (TAILQ_EMPTY(&m->md.pv_list) &&
+		    (m->flags & PG_FICTITIOUS) == 0) {
+			pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
+			if (TAILQ_EMPTY(&pvh->pv_list))
+				vm_page_aflag_clear(m, PGA_WRITEABLE);
+		}
 	}
 	return (pmap_unuse_pt(pmap, va, ptepde, free));
 }