svn commit: r274688 - projects/sendfile/sys/vm

[Gleb Smirnoff]

Author: glebius
Date: Wed Nov 19 06:13:55 2014
New Revision: 274688
URL: https://svnweb.freebsd.org/changeset/base/274688

Log:
  Provide emulation of asynchronous operation in swap_pager.c itself, not
  in the vm_pager.h inliner.
  
  Suggested by:	kib
  Sponsored by:	Netflix
  Sponsored by:	Nginx, Inc.

Modified:
  projects/sendfile/sys/vm/swap_pager.c
  projects/sendfile/sys/vm/vm_pager.h

Modified: projects/sendfile/sys/vm/swap_pager.c
==============================================================================
--- projects/sendfile/sys/vm/swap_pager.c	Wed Nov 19 05:58:34 2014	(r274687)
+++ projects/sendfile/sys/vm/swap_pager.c	Wed Nov 19 06:13:55 2014	(r274688)
@@ -361,6 +361,8 @@ static vm_object_t
 		    vm_prot_t prot, vm_ooffset_t offset, struct ucred *);
 static void	swap_pager_dealloc(vm_object_t object);
 static int	swap_pager_getpages(vm_object_t, vm_page_t *, int, int);
+static int	swap_pager_getpages_async(vm_object_t, vm_page_t *, int, int,
+    void(*)(void  *, vm_page_t *, int, int), void *);
 static void	swap_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *);
 static boolean_t
 		swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, int *after);
@@ -373,6 +375,7 @@ struct pagerops swappagerops = {
 	.pgo_alloc =	swap_pager_alloc,	/* allocate an OBJT_SWAP object		*/
 	.pgo_dealloc =	swap_pager_dealloc,	/* deallocate an OBJT_SWAP object	*/
 	.pgo_getpages =	swap_pager_getpages,	/* pagein				*/
+	.pgo_getpages_async = swap_pager_getpages_async, /* pagein (async)		*/
 	.pgo_putpages =	swap_pager_putpages,	/* pageout				*/
 	.pgo_haspage =	swap_pager_haspage,	/* get backing store status for page	*/
 	.pgo_pageunswapped = swap_pager_unswapped,	/* remove swap related to page		*/
@@ -1257,6 +1260,26 @@ swap_pager_getpages(vm_object_t object, 
 }
 
 /*
+ * 	swap_pager_getpages_async():
+ *
+ *	Right now this is emulation of asynchronous operation on top of
+ *	swap_pager_getpages().
+ */
+static int
+swap_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
+    int reqpage, void(*iodone)(void  *, vm_page_t *, int, int), void *arg)
+{
+	int r;
+
+	r = swap_pager_getpages(object, m, count, reqpage);
+	VM_OBJECT_WUNLOCK(object);
+	(iodone)(arg, m, count, r);
+	VM_OBJECT_WLOCK(object);
+
+	return (r);
+}
+
+/*
  *	swap_pager_putpages:
  *
  *	Assign swap (if necessary) and initiate I/O on the specified pages.

Modified: projects/sendfile/sys/vm/vm_pager.h
==============================================================================
--- projects/sendfile/sys/vm/vm_pager.h	Wed Nov 19 05:58:34 2014	(r274687)
+++ projects/sendfile/sys/vm/vm_pager.h	Wed Nov 19 06:13:55 2014	(r274688)
@@ -145,17 +145,8 @@ vm_pager_get_pages_async(vm_object_t obj
 	int r;
 
 	VM_OBJECT_ASSERT_WLOCKED(object);
-
-	if (*pagertab[object->type]->pgo_getpages_async == NULL) {
-		/* Emulate async operation. */
-		r = vm_pager_get_pages(object, m, count, reqpage);
-		VM_OBJECT_WUNLOCK(object);
-		(iodone)(arg, m, count, r);
-		VM_OBJECT_WLOCK(object);
-	} else
-		r = (*pagertab[object->type]->pgo_getpages_async)(object, m,
-		    count, reqpage, iodone, arg);
-
+	r = (*pagertab[object->type]->pgo_getpages_async)(object, m, count,
+	    reqpage, iodone, arg);
 	return (r);
 }