Reduce code duplication and exposure of direct access to struct

vm_page oflags by providing helper function
vm_page_readahead_finish(), which handles completed reads for pages
with indexes other then the requested one, for VOP_GETPAGES().

Reviewed by:	alc
MFC after:	1 week

1 files changed, 33 insertions, 0 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 53353e9..b679290 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -695,6 +695,39 @@ vm_page_free_zero(vm_page_t m)
 }
 
 /*
+ * Unbusy and handle the page queueing for a page from the VOP_GETPAGES()
+ * array which is not the request page.
+ */
+void
+vm_page_readahead_finish(vm_page_t m, int error)
+{
+
+	if (error == 0) {
+		/*
+		 * Since the page is not the requested page, whether
+		 * it should be activated or deactivated is not
+		 * obvious.  Empirical results have shown that
+		 * deactivating the page is usually the best choice,
+		 * unless the page is wanted by another thread.
+		 */
+		if (m->oflags & VPO_WANTED) {
+			vm_page_lock(m);
+			vm_page_activate(m);
+			vm_page_unlock(m);
+		} else {
+			vm_page_lock(m);
+			vm_page_deactivate(m);
+			vm_page_unlock(m);
+		}
+		vm_page_wakeup(m);
+	} else {
+		vm_page_lock(m);
+		vm_page_free(m);
+		vm_page_unlock(m);
+	}
+}
+
+/*
  *	vm_page_sleep:
  *
  *	Sleep and release the page and page queues locks.