[src/trunk]: src/sys/rump/librump/rumpkern In case a temp thread is exiting, ...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7ffc93f58c0c
branches:  trunk
changeset: 748831:7ffc93f58c0c
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Nov 06 16:15:16 2009 +0000

description:
In case a temp thread is exiting, borrow lwp0 for the respective
kmem_free().

diffstat:

 sys/rump/librump/rumpkern/scheduler.c |  28 +++++++++++++++++++++++++---
 1 files changed, 25 insertions(+), 3 deletions(-)

diffs (51 lines):

diff -r 5b77ce68deae -r 7ffc93f58c0c sys/rump/librump/rumpkern/scheduler.c
--- a/sys/rump/librump/rumpkern/scheduler.c     Fri Nov 06 15:41:58 2009 +0000
+++ b/sys/rump/librump/rumpkern/scheduler.c     Fri Nov 06 16:15:16 2009 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: scheduler.c,v 1.5 2009/11/04 18:11:11 pooka Exp $     */
+/*      $NetBSD: scheduler.c,v 1.6 2009/11/06 16:15:16 pooka Exp $     */
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: scheduler.c,v 1.5 2009/11/04 18:11:11 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: scheduler.c,v 1.6 2009/11/06 16:15:16 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/cpu.h>
@@ -147,9 +147,31 @@
        KASSERT(l->l_mutex == l->l_cpu->ci_schedstate.spc_mutex);
        rump_unschedule_cpu(l);
        l->l_mutex = NULL;
+
+       /*
+        * If we're using a temp lwp, need to take lwp0 for rump_lwp_free().
+        * (we could maybe cache idle lwp's to avoid constant bouncing)
+        */
        if (l->l_flag & LW_WEXIT) {
-               kmem_free(l, sizeof(*l));
                rumpuser_set_curlwp(NULL);
+
+               /* busy lwp0 */
+               rumpuser_mutex_enter_nowrap(schedmtx);
+               while (lwp0busy)
+                       rumpuser_cv_wait_nowrap(lwp0cv, schedmtx);
+               lwp0busy = true;
+               rumpuser_mutex_exit(schedmtx);
+
+               rump_schedule_cpu(&lwp0);
+               rumpuser_set_curlwp(&lwp0);
+               rump_lwp_free(l);
+               rump_unschedule_cpu(&lwp0);
+               rumpuser_set_curlwp(NULL);
+
+               rumpuser_mutex_enter_nowrap(schedmtx);
+               lwp0busy = false;
+               rumpuser_cv_signal(lwp0cv);
+               rumpuser_mutex_exit(schedmtx);
        }
 }