On 21-10-19, 14:28, Sudeep Holla wrote:
> Commit 099967699ad9 ("cpufreq: Cancel policy update work scheduled before
> freeing")
> added cancel_work_sync(policy->update) after the frequency QoS were
> removed. We can cancel the work just after taking the last CPU in the
> policy offline and unregistering the notifiers as policy->update cannot
> be scheduled from anywhere at this point.
>
> However, due to other bugs, doing so still triggered the race between
> freeing of policy and scheduled policy update work. Now that all those
> issues are resolved, we can move this cancelling of any scheduled policy
> update work just after removing min/max notifiers.
>
> Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
> ---
> drivers/cpufreq/cpufreq.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> Hi Rafael,
>
> Based on Viresh's suggestion, I am posting a patch to move this
> cancel_work_sync earlier though it's not a must have change.
For me it is :)
> I will leave it up to your preference.
>
> Regards,
> Sudeep
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 829a3764df1b..48a224a6b178 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1268,6 +1268,9 @@ static void cpufreq_policy_free(struct cpufreq_policy
> *policy)
> freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
> &policy->nb_min);
>
> + /* Cancel any pending policy->update work before freeing the policy. */
> + cancel_work_sync(&policy->update);
> +
> if (policy->max_freq_req) {
> /*
> * CPUFREQ_CREATE_POLICY notification is sent only after
> @@ -1279,8 +1282,6 @@ static void cpufreq_policy_free(struct cpufreq_policy
> *policy)
> }
>
> freq_qos_remove_request(policy->min_freq_req);
> - /* Cancel any pending policy->update work before freeing the policy. */
> - cancel_work_sync(&policy->update);
> kfree(policy->min_freq_req);
>
> cpufreq_policy_put_kobj(policy);
Thanks for doing this.
Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
--
viresh
