On Tue, Oct 22, 2019 at 12:07 PM Viresh Kumar <viresh.ku...@linaro.org> wrote: > > On 22-10-19, 11:46, Rafael J. Wysocki wrote: > > On Tue, Oct 22, 2019 at 4:25 AM Viresh Kumar <viresh.ku...@linaro.org> > > wrote: > > > > > > 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> > > > > Folded into the previous patch and applied. > > > > Please double check the result in the current linux-next branch in my tree. > > I would have kept the blank line after cancel_work_sync() which isn't > there anymore.
OK, it looks better with the extra blank line, so updated. Thanks!