Messages in this thread | | | Date | Sun, 21 Jul 2019 20:40:16 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.2 190/249] cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update() |
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On Tue, Jul 16, 2019 at 11:25:00AM +0200, Rafael J. Wysocki wrote: >On 7/15/2019 3:45 PM, Sasha Levin wrote: >>From: Viresh Kumar <viresh.kumar@linaro.org> >> >>[ Upstream commit 70a59fde6e69d1d8579f84bf4555bfffb3ce452d ] >> >>On some occasions cpufreq_verify_current_freq() schedules a work whose >>callback is handle_update(), which further calls cpufreq_update_policy() >>which may end up calling cpufreq_verify_current_freq() again. >> >>On the other hand, when cpufreq_update_policy() is called from >>handle_update(), the pointer to the cpufreq policy is already >>available, but cpufreq_cpu_acquire() is still called to get it in >>cpufreq_update_policy(), which should be avoided as well. >> >>To fix these issues, create a new helper, refresh_frequency_limits(), >>and make both handle_update() call it cpufreq_update_policy(). >> >>Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> >>[ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ] >>[ rjw: Changelog ] >>Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >>Signed-off-by: Sasha Levin <sashal@kernel.org> >>--- >> drivers/cpufreq/cpufreq.c | 26 ++++++++++++++++---------- >> 1 file changed, 16 insertions(+), 10 deletions(-) >> >>diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c >>index e84bf0eb7239..876a4cb09de3 100644 >>--- a/drivers/cpufreq/cpufreq.c >>+++ b/drivers/cpufreq/cpufreq.c >>@@ -1114,13 +1114,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp >> return ret; >> } >>+static void refresh_frequency_limits(struct cpufreq_policy *policy) >>+{ >>+ struct cpufreq_policy new_policy = *policy; >>+ >>+ pr_debug("updating policy for CPU %u\n", policy->cpu); >>+ >>+ new_policy.min = policy->user_policy.min; >>+ new_policy.max = policy->user_policy.max; >>+ >>+ cpufreq_set_policy(policy, &new_policy); >>+} >>+ >> static void handle_update(struct work_struct *work) >> { >> struct cpufreq_policy *policy = >> container_of(work, struct cpufreq_policy, update); >>- unsigned int cpu = policy->cpu; >>- pr_debug("handle_update for cpu %u called\n", cpu); >>- cpufreq_update_policy(cpu); >>+ >>+ pr_debug("handle_update for cpu %u called\n", policy->cpu); >>+ refresh_frequency_limits(policy); >> } >> static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) >>@@ -2392,7 +2404,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy, >> void cpufreq_update_policy(unsigned int cpu) >> { >> struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); >>- struct cpufreq_policy new_policy; >> if (!policy) >> return; >>@@ -2405,12 +2416,7 @@ void cpufreq_update_policy(unsigned int cpu) >> (cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy)))) >> goto unlock; >>- pr_debug("updating policy for CPU %u\n", cpu); >>- memcpy(&new_policy, policy, sizeof(*policy)); >>- new_policy.min = policy->user_policy.min; >>- new_policy.max = policy->user_policy.max; >>- >>- cpufreq_set_policy(policy, &new_policy); >>+ refresh_frequency_limits(policy); >> unlock: >> cpufreq_cpu_release(policy); > >I don't think this is suitable for -stable.
I've dropped it, thanks!
-- Thanks, Sasha
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