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Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: silence PROVE_RCU in sched_fork()
  idr: fix RCU lockdep splat in idr_get_next()
  rcu: apply RCU protection to wake_affine()
This commit is contained in:
Linus Torvalds
2010-06-28 12:17:40 -07:00
parent ab8aadbda7 8695159967
commit e6cb6281ef
3 changed files with 13 additions and 2 deletions
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9
kernel/sched.c
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@@ -2494,7 +2494,16 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (p->sched_class->task_fork) if (p->sched_class->task_fork)
p->sched_class->task_fork(p); p->sched_class->task_fork(p);
/*
* The child is not yet in the pid-hash so no cgroup attach races,
* and the cgroup is pinned to this child due to cgroup_fork()
* is ran before sched_fork().
*
* Silence PROVE_RCU.
*/
rcu_read_lock();
set_task_cpu(p, cpu); set_task_cpu(p, cpu);
rcu_read_unlock();
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on())) if (likely(sched_info_on()))

2
kernel/sched_fair.c
View File

@@ -1240,6 +1240,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
* effect of the currently running task from the load * effect of the currently running task from the load
* of the current CPU: * of the current CPU:
*/ */
rcu_read_lock();
if (sync) { if (sync) {
tg = task_group(current); tg = task_group(current);
weight = current->se.load.weight; weight = current->se.load.weight;
@@ -1275,6 +1276,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
balanced = this_eff_load <= prev_eff_load; balanced = this_eff_load <= prev_eff_load;
} else } else
balanced = true; balanced = true;
rcu_read_unlock();
/* /*
* If the currently running task will sleep within * If the currently running task will sleep within

4
lib/idr.c
View File

@@ -602,7 +602,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
/* find first ent */ /* find first ent */
n = idp->layers * IDR_BITS; n = idp->layers * IDR_BITS;
max = 1 << n; max = 1 << n;
p = rcu_dereference(idp->top); p = rcu_dereference_raw(idp->top);
if (!p) if (!p)
return NULL; return NULL;
@@ -610,7 +610,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
while (n > 0 && p) { while (n > 0 && p) {
n -= IDR_BITS; n -= IDR_BITS;
*paa++ = p; *paa++ = p;
p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
} }
if (p) { if (p) {