From e14929c6989db22f3eeaef4e343f050bb156e2cd Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 9 Dec 2009 10:15:01 +0000
Subject: [PATCH] --- yaml --- r: 178021 b: refs/heads/master c:
 23f5d142519621b16cf2b378cf8adf4dcf01a616 h: refs/heads/master i:   178019:
 acbbd1fac45b5962a7274b6e35077b531205a290 v: v3

---
 [refs]               |  2 +-
 trunk/kernel/sched.c | 16 ++++++----------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/[refs] b/[refs]
index 1aea31191fe5..476fb54c5493 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5fe85be081edf0ac92d83f9c39e0ab5c1371eb82
+refs/heads/master: 23f5d142519621b16cf2b378cf8adf4dcf01a616
diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
index 1782beed2fa7..79893123325c 100644
--- a/trunk/kernel/sched.c
+++ b/trunk/kernel/sched.c
@@ -6516,22 +6516,18 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
 	int retval;
 
 	get_online_cpus();
-	read_lock(&tasklist_lock);
+	rcu_read_lock();
 
 	p = find_process_by_pid(pid);
 	if (!p) {
-		read_unlock(&tasklist_lock);
+		rcu_read_unlock();
 		put_online_cpus();
 		return -ESRCH;
 	}
 
-	/*
-	 * It is not safe to call set_cpus_allowed with the
-	 * tasklist_lock held. We will bump the task_struct's
-	 * usage count and then drop tasklist_lock.
-	 */
+	/* Prevent p going away */
 	get_task_struct(p);
-	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
 
 	if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
 		retval = -ENOMEM;
@@ -6617,7 +6613,7 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
 	int retval;
 
 	get_online_cpus();
-	read_lock(&tasklist_lock);
+	rcu_read_lock();
 
 	retval = -ESRCH;
 	p = find_process_by_pid(pid);
@@ -6633,7 +6629,7 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
 	task_rq_unlock(rq, &flags);
 
 out_unlock:
-	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
 	put_online_cpus();
 
 	return retval;