lkml.org 
[lkml]   [2009]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [patch 1/4] kernel call_rcu usage: initialize rcu_head structures (v2)
Initialize rcu_head structures before passing them to call_rcu() to eliminate
false positives in DEBUG_RCU_HEAD.

Update: init at structure allocation time rather than just before
calling call_rcu(). Ensures we do not void the debug race test.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: mingo@elte.hu
CC: akpm@linux-foundation.org
---
kernel/fork.c | 1 +
kernel/pid.c | 1 +
kernel/rcupdate.c | 1 +
3 files changed, 3 insertions(+)

Index: linux-2.6-lttng/kernel/rcupdate.c
===================================================================
--- linux-2.6-lttng.orig/kernel/rcupdate.c 2009-10-06 10:34:25.000000000 -0400
+++ linux-2.6-lttng/kernel/rcupdate.c 2009-10-06 11:17:16.000000000 -0400
@@ -90,6 +90,7 @@ void synchronize_rcu(void)
if (rcu_blocking_is_gp())
return;

+ INIT_RCU_HEAD(&rcu.head);
init_completion(&rcu.completion);
/* Will wake me after RCU finished. */
call_rcu(&rcu.head, wakeme_after_rcu);
Index: linux-2.6-lttng/kernel/pid.c
===================================================================
--- linux-2.6-lttng.orig/kernel/pid.c 2009-10-06 10:34:25.000000000 -0400
+++ linux-2.6-lttng/kernel/pid.c 2009-10-06 11:12:46.000000000 -0400
@@ -264,6 +264,7 @@ struct pid *alloc_pid(struct pid_namespa

get_pid_ns(ns);
pid->level = ns->level;
+ INIT_RCU_HEAD(&pid->rcu);
atomic_set(&pid->count, 1);
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
Index: linux-2.6-lttng/kernel/fork.c
===================================================================
--- linux-2.6-lttng.orig/kernel/fork.c 2009-10-06 11:11:10.000000000 -0400
+++ linux-2.6-lttng/kernel/fork.c 2009-10-06 11:11:54.000000000 -0400
@@ -1012,6 +1012,7 @@ static struct task_struct *copy_process(
p->rcu_read_lock_nesting = 0;
p->rcu_flipctr_idx = 0;
#endif /* #ifdef CONFIG_PREEMPT_RCU */
+ INIT_RCU_HEAD(&p->rcu);
p->vfork_done = NULL;
spin_lock_init(&p->alloc_lock);

--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68

\
 
 \ /
  Last update: 2009-10-06 17:35    [W:0.102 / U:1.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site