From mboxrd@z Thu Jan  1 00:00:00 1970
From: mathieu.desnoyers@efficios.com (Mathieu Desnoyers)
Date: Thu, 29 Sep 2011 15:53:59 -0400
Subject: [ltt-dev] [PATCH 6/7] urcu,
	call_rcu: Cleanup call_rcu_data pointers	before used in child
In-Reply-To: <0f645da2f35f5c974a7059655e7b2e199cf98f72.1317198301.git.laijs@cn.fujitsu.com>
References: <cover.1317198301.git.laijs@cn.fujitsu.com>
	<0f645da2f35f5c974a7059655e7b2e199cf98f72.1317198301.git.laijs@cn.fujitsu.com>
Message-ID: <20110929195359.GA12159@Krystal>

Merged, with some changes:

commit 60af049d5e1d17e7ffdfd139bb486bd969c6a76c
Author: Lai Jiangshan <laijs at cn.fujitsu.com>
Date:   Thu Sep 29 15:56:43 2011 -0400

    urcu,call_rcu: Cleanup call_rcu_data pointers before use in child
    
    [ Edit by Mathieu Desnoyers: create maxcpus_reset to handle cases where
      maxcpus is 0 and -1, depending on the configuration. ]
    
    Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>

diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
index d964c47..0a47d96 100644
--- a/urcu-call-rcu-impl.h
+++ b/urcu-call-rcu-impl.h
@@ -88,6 +88,11 @@ static struct call_rcu_data *default_call_rcu_data;
 static struct call_rcu_data **per_cpu_call_rcu_data;
 static long maxcpus;
 
+static void maxcpus_reset(void)
+{
+	maxcpus = 0;
+}
+
 /* Allocate the array if it has not already been allocated. */
 
 static void alloc_cpu_call_rcu_data(void)
@@ -123,6 +128,10 @@ static void alloc_cpu_call_rcu_data(void)
 static struct call_rcu_data **per_cpu_call_rcu_data = NULL;
 static const long maxcpus = -1;
 
+static void maxcpus_reset(void)
+{
+}
+
 static void alloc_cpu_call_rcu_data(void)
 {
 }
@@ -688,6 +697,12 @@ void call_rcu_after_fork_child(void)
 	default_call_rcu_data = NULL;
 	(void)get_default_call_rcu_data();
 
+	/* Cleanup call_rcu_data pointers before use */
+	maxcpus_reset();
+	free(per_cpu_call_rcu_data);
+	per_cpu_call_rcu_data = NULL;
+	thread_call_rcu_data = NULL;
+
 	/* Dispose of all of the rest of the call_rcu_data structures. */
 	cds_list_for_each_entry_safe(crdp, next, &call_rcu_data_list, list) {
 		if (crdp == default_call_rcu_data)

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com