[src/trunk]: src/sys Use a queue of deferred entries to delete routes instead...

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

details:   https://anonhg.NetBSD.org/src/rev/284b7c049f1b
branches:  trunk
changeset: 358610:284b7c049f1b
user:      christos <christos%NetBSD.org@localhost>
date:      Tue Jan 09 19:52:29 2018 +0000

description:
Use a queue of deferred entries to delete routes instead of a fixed stack
of 10. Otherwise we can overflow in route deletions from the rexmit timer.
XXX: pullup-8

diffstat:

 sys/net/route.c |  36 +++++++++++++++---------------------
 sys/net/route.h |   5 +++--
 sys/sys/param.h |   4 ++--
 3 files changed, 20 insertions(+), 25 deletions(-)

diffs (121 lines):

diff -r 015e153a851d -r 284b7c049f1b sys/net/route.c
--- a/sys/net/route.c   Tue Jan 09 17:58:09 2018 +0000
+++ b/sys/net/route.c   Tue Jan 09 19:52:29 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.c,v 1.202 2018/01/05 01:53:15 christos Exp $     */
+/*     $NetBSD: route.c,v 1.203 2018/01/09 19:52:29 christos 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 1.202 2018/01/05 01:53:15 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.203 2018/01/09 19:52:29 christos Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -255,7 +255,7 @@
        struct workqueue        *wq;
        struct work             wk;
        kmutex_t                lock;
-       struct rtentry          *queue[10];
+       SLIST_HEAD(, rtentry)   queue;
 } rt_free_global __cacheline_aligned;
 
 /* psref for rtentry */
@@ -458,6 +458,8 @@
 #endif
 
        mutex_init(&rt_free_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
+       SLIST_INIT(&rt_free_global.queue);
+
        rt_psref_class = psref_class_create("rtentry", IPL_SOFTNET);
 
        error = workqueue_create(&rt_free_global.wq, "rt_free",
@@ -687,20 +689,19 @@
 rt_free_work(struct work *wk, void *arg)
 {
 
-restart:
-       mutex_enter(&rt_free_global.lock);
-       for (size_t i = 0; i < __arraycount(rt_free_global.queue); i++) {
-               if (rt_free_global.queue[i] == NULL)
-                       continue;
-               struct rtentry *rt = rt_free_global.queue[i];
-               rt_free_global.queue[i] = NULL;
+       for (;;) {
+               struct rtentry *rt;
+
+               mutex_enter(&rt_free_global.lock);
+               if ((rt = SLIST_FIRST(&rt_free_global.queue)) == NULL) {
+                       mutex_exit(&rt_free_global.lock);
+                       return;
+               }
+               SLIST_REMOVE_HEAD(&rt_free_global.queue, rt_free);
                mutex_exit(&rt_free_global.lock);
-
                atomic_dec_uint(&rt->rt_refcnt);
                _rt_free(rt);
-               goto restart;
        }
-       mutex_exit(&rt_free_global.lock);
 }
 
 void
@@ -714,16 +715,9 @@
                return;
        }
 
-       size_t i;
        mutex_enter(&rt_free_global.lock);
-       for (i = 0; i < __arraycount(rt_free_global.queue); i++) {
-               if (rt_free_global.queue[i] == NULL)
-                       break;
-       }
-
-       KASSERT(i < __arraycount(rt_free_global.queue));
-       rt_free_global.queue[i] = rt;
        rt_ref(rt);
+       SLIST_INSERT_HEAD(&rt_free_global.queue, rt, rt_free);
        mutex_exit(&rt_free_global.lock);
        workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
 }
diff -r 015e153a851d -r 284b7c049f1b sys/net/route.h
--- a/sys/net/route.h   Tue Jan 09 17:58:09 2018 +0000
+++ b/sys/net/route.h   Tue Jan 09 19:52:29 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.h,v 1.116 2017/12/18 04:11:13 ozaki-r Exp $      */
+/*     $NetBSD: route.h,v 1.117 2018/01/09 19:52:29 christos Exp $     */
 
 /*
  * Copyright (c) 1980, 1986, 1993
@@ -124,7 +124,8 @@
        struct  sockaddr *rt_tag;       /* route tagging info */
 #ifdef _KERNEL
        kcondvar_t rt_cv;
-       struct psref_target     rt_psref;
+       struct psref_target rt_psref;
+       SLIST_ENTRY(rtentry) rt_free;   /* queue of deferred frees */
 #endif
 };
 
diff -r 015e153a851d -r 284b7c049f1b sys/sys/param.h
--- a/sys/sys/param.h   Tue Jan 09 17:58:09 2018 +0000
+++ b/sys/sys/param.h   Tue Jan 09 19:52:29 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: param.h,v 1.556 2018/01/04 01:42:25 christos Exp $     */
+/*     $NetBSD: param.h,v 1.557 2018/01/09 19:52:29 christos Exp $     */
 
 /*-
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -67,7 +67,7 @@
  *     2.99.9          (299000900)
  */
 
-#define        __NetBSD_Version__      899001100       /* NetBSD 8.99.11 */
+#define        __NetBSD_Version__      899001200       /* NetBSD 8.99.12 */
 
 #define __NetBSD_Prereq__(M,m,p) (((((M) * 100000000) + \
     (m) * 1000000) + (p) * 100) <= __NetBSD_Version__)