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| author | Xiaotian Feng <dfeng@redhat.com> | 2011-04-22 18:53:54 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-05-28 17:02:54 +0200 |
| commit | cd4ae6adf8b1c21d88e83ed56afeeef97b28f356 (patch) | |
| tree | 7a0625d20d135deb1e8c142fc13da6b4eaa6ea6c | |
| parent | dc7acbb2518f250050179c8581a972df3b6a24f1 (diff) | |
| download | linux-cd4ae6adf8b1c21d88e83ed56afeeef97b28f356.tar.bz2 | |
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@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1303469634-11678-1-git-send-email-dfeng@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/sched_rt.c | 10 | ||||
| -rw-r--r-- | 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 64b2a37c07d0..88725c939e0b 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 48ddf431db0e..331e01bcd026 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); |