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authorStephen Boyd <sboyd@codeaurora.org>2013-08-28 14:24:45 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-08-29 22:19:23 +0200
commit6932078376e2c1fd49b6c4aa41cc5e162ee83d8a (patch)
treea0cf45ee13656a926aab96789af763e8716bfc63 /drivers/cpufreq
parentc4afc410942f9f0675a5431adbdb03cf5908d1df (diff)
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>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq_governor.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 0e5929b3627..0806c31e576 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);