Re: [PATCH v2] cpufreq: Don't use smp_processor_id() in preemptible context

Viresh Kumar
2013-08-29T04:20:22Z

On 29 August 2013 02:54, Stephen Boyd <sboyd@codeaurora.org> wrote:
> 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>
> ---
> drivers/cpufreq/cpufreq_governor.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>