[src/trunk]: src/sys/rump/librump/rumpkern Don't allow kernel threads to run ...

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

details:   https://anonhg.NetBSD.org/src/rev/3160c329d49b
branches:  trunk
changeset: 785352:3160c329d49b
user:      pooka <pooka%NetBSD.org@localhost>
date:      Sun Mar 10 16:51:31 2013 +0000

description:
Don't allow kernel threads to run before all CPUs have been initialized
to avoid them getting scheduled on non-initialized CPUs.

diffstat:

 sys/rump/librump/rumpkern/rump.c         |   8 +++++-
 sys/rump/librump/rumpkern/rump_private.h |   5 +++-
 sys/rump/librump/rumpkern/threads.c      |  36 ++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 5 deletions(-)

diffs (124 lines):

diff -r 7e51c71498f0 -r 3160c329d49b sys/rump/librump/rumpkern/rump.c
--- a/sys/rump/librump/rumpkern/rump.c  Sun Mar 10 16:27:11 2013 +0000
+++ b/sys/rump/librump/rumpkern/rump.c  Sun Mar 10 16:51:31 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump.c,v 1.255 2013/03/08 19:04:28 pooka Exp $ */
+/*     $NetBSD: rump.c,v 1.256 2013/03/10 16:51:31 pooka Exp $ */
 
 /*
  * Copyright (c) 2007-2011 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rump.c,v 1.255 2013/03/08 19:04:28 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rump.c,v 1.256 2013/03/10 16:51:31 pooka Exp $");
 
 #include <sys/systm.h>
 #define ELFSIZE ARCH_ELFSIZE
@@ -267,6 +267,7 @@
        } else {
                numcpu = rumpuser_getnhostcpu();
        }
+       rump_thread_init();
        rump_cpus_bootstrap(&numcpu);
 
        rumpuser_gettime(&sec, &nsec, &error);
@@ -385,6 +386,9 @@
                aprint_verbose("cpu%d at thinair0: rump virtual cpu\n", i);
        }
 
+       /* CPUs are up.  allow kernel threads to run */
+       rump_thread_allow();
+
        mksysctls();
        kqueue_init();
        iostat_init();
diff -r 7e51c71498f0 -r 3160c329d49b sys/rump/librump/rumpkern/rump_private.h
--- a/sys/rump/librump/rumpkern/rump_private.h  Sun Mar 10 16:27:11 2013 +0000
+++ b/sys/rump/librump/rumpkern/rump_private.h  Sun Mar 10 16:51:31 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump_private.h,v 1.73 2013/02/19 09:04:54 martin Exp $ */
+/*     $NetBSD: rump_private.h,v 1.74 2013/03/10 16:51:31 pooka Exp $  */
 
 /*
  * Copyright (c) 2007-2011 Antti Kantee.  All Rights Reserved.
@@ -141,4 +141,7 @@
 
 void   rump_xc_highpri(struct cpu_info *);
 
+void   rump_thread_init(void);
+void   rump_thread_allow(void);
+
 #endif /* _SYS_RUMP_PRIVATE_H_ */
diff -r 7e51c71498f0 -r 3160c329d49b sys/rump/librump/rumpkern/threads.c
--- a/sys/rump/librump/rumpkern/threads.c       Sun Mar 10 16:27:11 2013 +0000
+++ b/sys/rump/librump/rumpkern/threads.c       Sun Mar 10 16:51:31 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: threads.c,v 1.17 2012/11/04 14:40:47 pooka Exp $       */
+/*     $NetBSD: threads.c,v 1.18 2013/03/10 16:51:31 pooka Exp $       */
 
 /*
  * Copyright (c) 2007-2009 Antti Kantee.  All Rights Reserved.
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: threads.c,v 1.17 2012/11/04 14:40:47 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: threads.c,v 1.18 2013/03/10 16:51:31 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -48,6 +48,10 @@
        struct lwp *mylwp;
 };
 
+static bool threads_are_go;
+static struct rumpuser_mtx *thrmtx;
+static struct rumpuser_cv *thrcv;
+
 static void *
 threadbouncer(void *arg)
 {
@@ -59,6 +63,15 @@
        f = k->f;
        thrarg = k->arg;
 
+       /* don't allow threads to run before all CPUs have fully attached */
+       if (!threads_are_go) {
+               rumpuser_mutex_enter_nowrap(thrmtx);
+               while (!threads_are_go) {
+                       rumpuser_cv_wait_nowrap(thrcv, thrmtx);
+               }
+               rumpuser_mutex_exit(thrmtx);
+       }
+
        /* schedule ourselves */
        rumpuser_set_curlwp(l);
        rump_schedule();
@@ -74,6 +87,25 @@
        panic("unreachable, should kthread_exit()");
 }
 
+void
+rump_thread_init(void)
+{
+
+       rumpuser_mutex_init(&thrmtx);
+       rumpuser_cv_init(&thrcv);
+}
+
+void
+rump_thread_allow(void)
+{
+
+       rumpuser_mutex_enter(thrmtx);
+       threads_are_go = true;
+       rumpuser_cv_broadcast(thrcv);
+       rumpuser_mutex_exit(thrmtx);
+
+}
+
 static struct {
        const char *t_name;
        bool t_ncmp;