Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>

    Replace various VM related page count calculations strewn over the
    VM code with inlines to aid in readability and to reduce fragility
    in the code where modules depend on the same test being performed
    to properly sleep and wakeup.

    Split out a portion of the page deactivation code into an inline
    in vm_page.c to support vm_page_dontneed().

    add vm_page_dontneed(), which handles the madvise MADV_DONTNEED
    feature in a related commit coming up for vm_map.c/vm_object.c.  This
    code prevents degenerate cases where an essentially active page may
    be rotated through a subset of the paging lists, resulting in premature
    disposal.

1 files changed, 3 insertions, 12 deletions

diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index e53079a..1d7157c 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -209,19 +209,9 @@ vm_fork(p1, p2, flags)
 		p1->p_vmspace->vm_refcnt++;
 	}
 
-	/*
-	 * Great, so we have a memory-heavy process and the 
-	 * entire machine comes to a screaching halt because
-	 * nobody can fork/exec anything.  What we really need
-	 * to do is fix the process swapper so it swaps out the right
-	 * processes.
-	 */
-#if 0
-	while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) {
-		vm_pageout_deficit += (UPAGES + VM_INITIAL_PAGEIN);
+	while (vm_page_count_severe()) {
 		VM_WAIT;
 	}
-#endif
 
 	if ((flags & RFMEM) == 0) {
 		p2->p_vmspace = vmspace_fork(p1->p_vmspace);
@@ -339,8 +329,9 @@ scheduler(dummy)
 	int ppri;
 
 loop:
-	while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) {
+	if (vm_page_count_min()) {
 		VM_WAIT;
+		goto loop;
 	}
 
 	pp = NULL;