Commit-ID: cd4ae6adf8b1c21d88e83ed56afeeef97b28f356
Gitweb: http://git.kernel.org/tip/cd4ae6adf8b1c21d88e83ed56afeeef97b28f356
Author: Xiaotian Feng <dfeng@xxxxxxxxxx>
AuthorDate: Fri, 22 Apr 2011 18:53:54 +0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sat, 28 May 2011 17:02:54 +0200
sched: More sched_domain iterations fixes
sched_domain iterations needs to be protected by rcu_read_lock() now,
this patch adds another two places which needs the rcu lock, which is
spotted by following suspicious rcu_dereference_check() usage warnings.
kernel/sched_rt.c:1244 invoked rcu_dereference_check() without protection!
kernel/sched_stats.h:41 invoked rcu_dereference_check() without protection!
Signed-off-by: Xiaotian Feng <dfeng@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1303469634-11678-1-git-send-email-dfeng@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched_rt.c | 10 ++++++++--
kernel/sched_stats.h | 4 ++--
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 64b2a37..88725c9 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1263,6 +1263,7 @@ static int find_lowest_rq(struct task_struct *task)
if (!cpumask_test_cpu(this_cpu, lowest_mask))
this_cpu = -1; /* Skip this_cpu opt if not among lowest */
+ rcu_read_lock();
for_each_domain(cpu, sd) {
if (sd->flags & SD_WAKE_AFFINE) {
int best_cpu;
@@ -1272,15 +1273,20 @@ static int find_lowest_rq(struct task_struct *task)
* remote processor.
*/
if (this_cpu != -1 &&
- cpumask_test_cpu(this_cpu, sched_domain_span(sd)))
+ cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
+ rcu_read_unlock();
return this_cpu;
+ }
best_cpu = cpumask_first_and(lowest_mask,
sched_domain_span(sd));
- if (best_cpu < nr_cpu_ids)
+ if (best_cpu < nr_cpu_ids) {
+ rcu_read_unlock();
return best_cpu;
+ }
}
}
+ rcu_read_unlock();
/*
* And finally, if there were no matches within the domains
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 48ddf43..331e01b 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -37,7 +37,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
#ifdef CONFIG_SMP
/* domain-specific stats */
- preempt_disable();
+ rcu_read_lock();
for_each_domain(cpu, sd) {
enum cpu_idle_type itype;
@@ -64,7 +64,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
sd->ttwu_wake_remote, sd->ttwu_move_affine,
sd->ttwu_move_balance);
}
- preempt_enable();
+ rcu_read_unlock();
#endif
}
kfree(mask_str);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|