[src/trunk]: src/sys/net Prevent rt_free_global.wk from being enqueued to wor...

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b88ffcd24858
branches:  trunk
changeset: 829418:b88ffcd24858
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Tue Jan 30 11:01:04 2018 +0000

description:
Prevent rt_free_global.wk from being enqueued to workqueue doubly

diffstat:

 sys/net/route.c |  12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diffs (55 lines):

diff -r 2cb7d98b83a3 -r b88ffcd24858 sys/net/route.c
--- a/sys/net/route.c   Tue Jan 30 10:40:02 2018 +0000
+++ b/sys/net/route.c   Tue Jan 30 11:01:04 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.c,v 1.205 2018/01/23 07:20:10 ozaki-r Exp $      */
+/*     $NetBSD: route.c,v 1.206 2018/01/30 11:01:04 ozaki-r Exp $      */
 
 /*-
  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.205 2018/01/23 07:20:10 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.206 2018/01/30 11:01:04 ozaki-r Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -256,6 +256,7 @@
        struct work             wk;
        kmutex_t                lock;
        SLIST_HEAD(, rtentry)   queue;
+       bool                    enqueued;
 } rt_free_global __cacheline_aligned;
 
 /* psref for rtentry */
@@ -459,6 +460,7 @@
 
        mutex_init(&rt_free_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
        SLIST_INIT(&rt_free_global.queue);
+       rt_free_global.enqueued = false;
 
        rt_psref_class = psref_class_create("rtentry", IPL_SOFTNET);
 
@@ -693,6 +695,7 @@
                struct rtentry *rt;
 
                mutex_enter(&rt_free_global.lock);
+               rt_free_global.enqueued = false;
                if ((rt = SLIST_FIRST(&rt_free_global.queue)) == NULL) {
                        mutex_exit(&rt_free_global.lock);
                        return;
@@ -718,8 +721,11 @@
        mutex_enter(&rt_free_global.lock);
        rt_ref(rt);
        SLIST_INSERT_HEAD(&rt_free_global.queue, rt, rt_free);
+       if (!rt_free_global.enqueued) {
+               workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
+               rt_free_global.enqueued = true;
+       }
        mutex_exit(&rt_free_global.lock);
-       workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
 }
 
 #ifdef NET_MPSAFE