Migrate the thread stack management functions from the machine-dependent

to the machine-independent parts of the VM.  At the same time, this
introduces vm object locking for the non-i386 platforms.

Two details:

1. KSTACK_GUARD has been removed in favor of KSTACK_GUARD_PAGES.  The
different machine-dependent implementations used various combinations
of KSTACK_GUARD and KSTACK_GUARD_PAGES.  To disable guard page, set
KSTACK_GUARD_PAGES to 0.

2. Remove the (unnecessary) clearing of PG_ZERO in vm_thread_new.  In
5.x, (but not 4.x,) PG_ZERO can only be set if VM_ALLOC_ZERO is passed
to vm_page_alloc() or vm_page_grab().

2 files changed, 1 insertions, 47 deletions

diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c
index dd6ba1d..77effaa 100644
--- a/sys/ia64/ia64/pmap.c
+++ b/sys/ia64/ia64/pmap.c
@@ -765,53 +765,6 @@ pmap_track_modified(vm_offset_t va)
 		return 0;
 }
 
-/*
- * Create the KSTACK for a new thread.
- * This routine directly affects the fork perf for a process/thread.
- */
-void
-pmap_new_thread(struct thread *td, int pages)
-{
-
-	/* Bounds check */
-	if (pages <= 1)
-		pages = KSTACK_PAGES;
-	else if (pages > KSTACK_MAX_PAGES)
-		pages = KSTACK_MAX_PAGES;
-	td->td_kstack = (vm_offset_t)malloc(pages * PAGE_SIZE, M_PMAP,
-	    M_WAITOK);
-	td->td_kstack_pages = pages;
-}
-
-/*
- * Dispose the KSTACK for a thread that has exited.
- * This routine directly impacts the exit perf of a process/thread.
- */
-void
-pmap_dispose_thread(struct thread *td)
-{
-
-	free((void*)td->td_kstack, M_PMAP);
-	td->td_kstack = 0;
-	td->td_kstack_pages = 0;
-}
-
-/*
- * Allow the KSTACK for a thread to be prejudicially paged out.
- */
-void
-pmap_swapout_thread(struct thread *td)
-{
-}
-
-/*
- * Bring the KSTACK for a specified thread back in.
- */
-void
-pmap_swapin_thread(struct thread *td)
-{
-}
-
 /***************************************************
  * Page table page management routines.....
  ***************************************************/
diff --git a/sys/ia64/include/param.h b/sys/ia64/include/param.h
index 2548fa6..1b3bf0c 100644
--- a/sys/ia64/include/param.h
+++ b/sys/ia64/include/param.h
@@ -135,6 +135,7 @@
 #define	SINCR		1		/* increment of stack/NBPG */
 
 #define	KSTACK_PAGES	4		/* pages of kernel stack */
+#define	KSTACK_GUARD_PAGES 0		/* pages of kstack guard; 0 disables */
 #define	UAREA_PAGES	1		/* pages of u-area */
 
 /*