With Alfred's permission, remove vm_mtx in favor of a fine-grained approach

(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.

1 files changed, 5 insertions, 10 deletions

diff --git a/sys/vm/vm_pager.h b/sys/vm/vm_pager.h
index b4511ca..427d103 100644
--- a/sys/vm/vm_pager.h
+++ b/sys/vm/vm_pager.h
@@ -124,12 +124,12 @@ vm_pager_get_pages(
 ) {
 	int r;
 
-	mtx_assert(&vm_mtx, MA_OWNED);
+	GIANT_REQUIRED;
+
 	r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
 	if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
 		vm_page_zero_invalid(m[reqpage], TRUE);
 	}
-	mtx_assert(&vm_mtx, MA_OWNED);
 	return(r);
 }
 
@@ -141,11 +141,9 @@ vm_pager_put_pages(
 	int flags,
 	int *rtvals
 ) {
-
-	mtx_assert(&vm_mtx, MA_OWNED);
+	GIANT_REQUIRED;
 	(*pagertab[object->type]->pgo_putpages)
 	    (object, m, count, flags, rtvals);
-	mtx_assert(&vm_mtx, MA_OWNED);
 }
 
 /*
@@ -168,10 +166,9 @@ vm_pager_has_page(
 ) {
 	boolean_t ret;
 
-	mtx_assert(&vm_mtx, MA_OWNED);
+	GIANT_REQUIRED;
 	ret = (*pagertab[object->type]->pgo_haspage)
 	    (object, offset, before, after);
-	mtx_assert(&vm_mtx, MA_OWNED);
 	return (ret);
 } 
 
@@ -186,11 +183,9 @@ vm_pager_has_page(
 static __inline void
 vm_pager_page_unswapped(vm_page_t m)
 {
-
-	mtx_assert(&vm_mtx, MA_OWNED);
+	GIANT_REQUIRED;
 	if (pagertab[m->object->type]->pgo_pageunswapped)
 		(*pagertab[m->object->type]->pgo_pageunswapped)(m);
-	mtx_assert(&vm_mtx, MA_OWNED);
 }
 
 #endif