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| author | Stephen Boyd <sboyd@codeaurora.org> | 2013-08-28 21:24:45 (GMT) |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-08-29 20:19:23 (GMT) |
| commit | 6932078376e2c1fd49b6c4aa41cc5e162ee83d8a (patch) | |
| tree | a0cf45ee13656a926aab96789af763e8716bfc63 | |
| parent | c4afc410942f9f0675a5431adbdb03cf5908d1df (diff) | |
| download | linux-fsl-qoriq-6932078376e2c1fd49b6c4aa41cc5e162ee83d8a.tar.xz | |
cpufreq: Don't use smp_processor_id() in preemptible context
Workqueues are preemptible even if works are queued on them with
queue_work_on(). Let's use raw_smp_processor_id() here to silence
the warning.
BUG: using smp_processor_id() in preemptible [00000000] code: kworker/3:2/674
caller is gov_queue_work+0x28/0xb0
CPU: 0 PID: 674 Comm: kworker/3:2 Tainted: G W 3.10.0 #30
Workqueue: events od_dbs_timer
[<c010c178>] (unwind_backtrace+0x0/0x11c) from [<c0109dec>] (show_stack+0x10/0x14)
[<c0109dec>] (show_stack+0x10/0x14) from [<c03885a4>] (debug_smp_processor_id+0xbc/0xf0)
[<c03885a4>] (debug_smp_processor_id+0xbc/0xf0) from [<c0635864>] (gov_queue_work+0x28/0xb0)
[<c0635864>] (gov_queue_work+0x28/0xb0) from [<c0635618>] (od_dbs_timer+0x108/0x134)
[<c0635618>] (od_dbs_timer+0x108/0x134) from [<c01aa8f8>] (process_one_work+0x25c/0x444)
[<c01aa8f8>] (process_one_work+0x25c/0x444) from [<c01aaf88>] (worker_thread+0x200/0x344)
[<c01aaf88>] (worker_thread+0x200/0x344) from [<c01b03bc>] (kthread+0xa0/0xb0)
[<c01b03bc>] (kthread+0xa0/0xb0) from [<c01061b8>] (ret_from_fork+0x14/0x3c)
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/cpufreq/cpufreq_governor.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index 0e5929b..0806c31 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -123,7 +123,14 @@ void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy, return; if (!all_cpus) { - __gov_queue_work(smp_processor_id(), dbs_data, delay); + /* + * Use raw_smp_processor_id() to avoid preemptible warnings. + * We know that this is only called with all_cpus == false from + * works that have been queued with *_work_on() functions and + * those works are canceled during CPU_DOWN_PREPARE so they + * can't possibly run on any other CPU. + */ + __gov_queue_work(raw_smp_processor_id(), dbs_data, delay); } else { for_each_cpu(i, policy->cpus) __gov_queue_work(i, dbs_data, delay); |