| Message ID | 20190109104236.6532-1-quentin.perret@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | cpufreq: scmi: Fix frequency invariance in slow path | expand |
On 09-01-19, 10:42, Quentin Perret wrote: > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > frequency changes to provide scale-invariant load-tracking signals to > the scheduler. However, in the slow path, it does so while specifying > the current and max frequencies in different units, hence resulting in a > broken freq_scale factor. > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > frequency table. > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > message protocol") > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > --- > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > index 50b1551ba894..3f0693439486 100644 > --- a/drivers/cpufreq/scmi-cpufreq.c > +++ b/drivers/cpufreq/scmi-cpufreq.c > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > int ret; > struct scmi_data *priv = policy->driver_data; > struct scmi_perf_ops *perf_ops = handle->perf_ops; > - u64 freq = policy->freq_table[index].frequency * 1000; > + u64 freq = policy->freq_table[index].frequency; > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > if (!ret) > arch_set_freq_scale(policy->related_cpus, freq, > policy->cpuinfo.max_freq); Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
On Wednesday, January 9, 2019 11:45:11 AM CET Viresh Kumar wrote: > On 09-01-19, 10:42, Quentin Perret wrote: > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > frequency changes to provide scale-invariant load-tracking signals to > > the scheduler. However, in the slow path, it does so while specifying > > the current and max frequencies in different units, hence resulting in a > > broken freq_scale factor. > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > frequency table. > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > message protocol") > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > --- > > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > > index 50b1551ba894..3f0693439486 100644 > > --- a/drivers/cpufreq/scmi-cpufreq.c > > +++ b/drivers/cpufreq/scmi-cpufreq.c > > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > > int ret; > > struct scmi_data *priv = policy->driver_data; > > struct scmi_perf_ops *perf_ops = handle->perf_ops; > > - u64 freq = policy->freq_table[index].frequency * 1000; > > + u64 freq = policy->freq_table[index].frequency; > > > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > > if (!ret) > > arch_set_freq_scale(policy->related_cpus, freq, > > policy->cpuinfo.max_freq); > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> This would be stable-candidate I guess?
On Wednesday 09 Jan 2019 at 11:56:06 (+0100), Rafael J. Wysocki wrote: > On Wednesday, January 9, 2019 11:45:11 AM CET Viresh Kumar wrote: > > On 09-01-19, 10:42, Quentin Perret wrote: > > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > > frequency changes to provide scale-invariant load-tracking signals to > > > the scheduler. However, in the slow path, it does so while specifying > > > the current and max frequencies in different units, hence resulting in a > > > broken freq_scale factor. > > > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > > frequency table. > > > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > > message protocol") > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > --- > > > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > > > index 50b1551ba894..3f0693439486 100644 > > > --- a/drivers/cpufreq/scmi-cpufreq.c > > > +++ b/drivers/cpufreq/scmi-cpufreq.c > > > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > > > int ret; > > > struct scmi_data *priv = policy->driver_data; > > > struct scmi_perf_ops *perf_ops = handle->perf_ops; > > > - u64 freq = policy->freq_table[index].frequency * 1000; > > > + u64 freq = policy->freq_table[index].frequency; > > > > > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > > > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > > > if (!ret) > > > arch_set_freq_scale(policy->related_cpus, freq, > > > policy->cpuinfo.max_freq); > > > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > > This would be stable-candidate I guess? I think so yes. I was hoping the 'Fixes:' tag would be enough ? Or do I still need to CC stable too ? Thanks, Quentin
On 09-01-19, 11:56, Rafael J. Wysocki wrote: > On Wednesday, January 9, 2019 11:45:11 AM CET Viresh Kumar wrote: > > On 09-01-19, 10:42, Quentin Perret wrote: > > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > > frequency changes to provide scale-invariant load-tracking signals to > > > the scheduler. However, in the slow path, it does so while specifying > > > the current and max frequencies in different units, hence resulting in a > > > broken freq_scale factor. > > > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > > frequency table. > > > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > > message protocol") > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > --- > > > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > > > index 50b1551ba894..3f0693439486 100644 > > > --- a/drivers/cpufreq/scmi-cpufreq.c > > > +++ b/drivers/cpufreq/scmi-cpufreq.c > > > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > > > int ret; > > > struct scmi_data *priv = policy->driver_data; > > > struct scmi_perf_ops *perf_ops = handle->perf_ops; > > > - u64 freq = policy->freq_table[index].frequency * 1000; > > > + u64 freq = policy->freq_table[index].frequency; > > > > > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > > > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > > > if (!ret) > > > arch_set_freq_scale(policy->related_cpus, freq, > > > policy->cpuinfo.max_freq); > > > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > > This would be stable-candidate I guess? Cc: 4.17+ <stable@vger.kernel.org> # v4.17+
On Wed, Jan 09, 2019 at 10:42:36AM +0000, Quentin Perret wrote: > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > frequency changes to provide scale-invariant load-tracking signals to > the scheduler. However, in the slow path, it does so while specifying > the current and max frequencies in different units, hence resulting in a > broken freq_scale factor. > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > frequency table. > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > message protocol") Good find. Acked-by: Sudeep Holla <sudeep.holla@arm.com> -- Regards, Sudeep
On Wednesday, January 9, 2019 11:59:05 AM CET Quentin Perret wrote: > On Wednesday 09 Jan 2019 at 11:56:06 (+0100), Rafael J. Wysocki wrote: > > On Wednesday, January 9, 2019 11:45:11 AM CET Viresh Kumar wrote: > > > On 09-01-19, 10:42, Quentin Perret wrote: > > > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > > > frequency changes to provide scale-invariant load-tracking signals to > > > > the scheduler. However, in the slow path, it does so while specifying > > > > the current and max frequencies in different units, hence resulting in a > > > > broken freq_scale factor. > > > > > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > > > frequency table. > > > > > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > > > message protocol") > > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > > --- > > > > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > > > > index 50b1551ba894..3f0693439486 100644 > > > > --- a/drivers/cpufreq/scmi-cpufreq.c > > > > +++ b/drivers/cpufreq/scmi-cpufreq.c > > > > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > > > > int ret; > > > > struct scmi_data *priv = policy->driver_data; > > > > struct scmi_perf_ops *perf_ops = handle->perf_ops; > > > > - u64 freq = policy->freq_table[index].frequency * 1000; > > > > + u64 freq = policy->freq_table[index].frequency; > > > > > > > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > > > > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > > > > if (!ret) > > > > arch_set_freq_scale(policy->related_cpus, freq, > > > > policy->cpuinfo.max_freq); > > > > > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > > > > This would be stable-candidate I guess? > > I think so yes. I was hoping the 'Fixes:' tag would be enough ? It doesn't cause -stable to pick up commits automatically if that's what you're asking about. > Or do I still need to CC stable too ? No, you don't need to (and should not) CC -stable yourself. You can, however, add a Cc: <stable..> tag to the patch which helps maintainers a bit.
On Wednesday 09 Jan 2019 at 12:03:49 (+0100), Rafael J. Wysocki wrote: > On Wednesday, January 9, 2019 11:59:05 AM CET Quentin Perret wrote: > > On Wednesday 09 Jan 2019 at 11:56:06 (+0100), Rafael J. Wysocki wrote: > > > On Wednesday, January 9, 2019 11:45:11 AM CET Viresh Kumar wrote: > > > > On 09-01-19, 10:42, Quentin Perret wrote: > > > > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > > > > frequency changes to provide scale-invariant load-tracking signals to > > > > > the scheduler. However, in the slow path, it does so while specifying > > > > > the current and max frequencies in different units, hence resulting in a > > > > > broken freq_scale factor. > > > > > > > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > > > > frequency table. > > > > > > > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > > > > message protocol") > > > > > Signed-off-by: Quentin Perret <quentin.perret@arm.com> > > > > > --- > > > > > drivers/cpufreq/scmi-cpufreq.c | 4 ++-- > > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > > > > > index 50b1551ba894..3f0693439486 100644 > > > > > --- a/drivers/cpufreq/scmi-cpufreq.c > > > > > +++ b/drivers/cpufreq/scmi-cpufreq.c > > > > > @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) > > > > > int ret; > > > > > struct scmi_data *priv = policy->driver_data; > > > > > struct scmi_perf_ops *perf_ops = handle->perf_ops; > > > > > - u64 freq = policy->freq_table[index].frequency * 1000; > > > > > + u64 freq = policy->freq_table[index].frequency; > > > > > > > > > > - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); > > > > > + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); > > > > > if (!ret) > > > > > arch_set_freq_scale(policy->related_cpus, freq, > > > > > policy->cpuinfo.max_freq); > > > > > > > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > > > > > > This would be stable-candidate I guess? > > > > I think so yes. I was hoping the 'Fixes:' tag would be enough ? > > It doesn't cause -stable to pick up commits automatically if that's > what you're asking about. > > > Or do I still need to CC stable too ? > > No, you don't need to (and should not) CC -stable yourself. > > You can, however, add a Cc: <stable..> tag to the patch which helps > maintainers a bit. OK, will do from now on. Thanks ! Quentin
On Wednesday, January 9, 2019 11:59:45 AM CET Sudeep Holla wrote: > On Wed, Jan 09, 2019 at 10:42:36AM +0000, Quentin Perret wrote: > > The scmi-cpufreq driver calls the arch_set_freq_scale() callback on > > frequency changes to provide scale-invariant load-tracking signals to > > the scheduler. However, in the slow path, it does so while specifying > > the current and max frequencies in different units, hence resulting in a > > broken freq_scale factor. > > > > Fix this by passing all frequencies in KHz, as stored in the CPUFreq > > frequency table. > > > > Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI > > message protocol") > > Good find. > > Acked-by: Sudeep Holla <sudeep.holla@arm.com> Applied, thanks!
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index 50b1551ba894..3f0693439486 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) int ret; struct scmi_data *priv = policy->driver_data; struct scmi_perf_ops *perf_ops = handle->perf_ops; - u64 freq = policy->freq_table[index].frequency * 1000; + u64 freq = policy->freq_table[index].frequency; - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false); if (!ret) arch_set_freq_scale(policy->related_cpus, freq, policy->cpuinfo.max_freq);
The scmi-cpufreq driver calls the arch_set_freq_scale() callback on frequency changes to provide scale-invariant load-tracking signals to the scheduler. However, in the slow path, it does so while specifying the current and max frequencies in different units, hence resulting in a broken freq_scale factor. Fix this by passing all frequencies in KHz, as stored in the CPUFreq frequency table. Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI message protocol") Signed-off-by: Quentin Perret <quentin.perret@arm.com> --- drivers/cpufreq/scmi-cpufreq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)