When boot with maxcpu=1 restrict, and LPI(Low Power Idle States) is on,
only CPU0 will go online. The support AMU flag of CPU0 will be set but the
flags of other CPUs will not. This will cause AMU FIE set up fail for CPU0
when it shares a cpufreq policy with other CPU(s). After that, when other
CPUs are finally online and the support AMU flags of them are set, they'll
never have a chance to set up AMU FIE, even though they're eligible.
To solve this problem, the process of setting up AMU FIE needs to be
modified as follows:
1. Set up AMU FIE only for the online CPUs.
2. Try to set up AMU FIE each time a CPU goes online and do the
freq_counters_valid() check. If this check fails, clear scale freq source
of all the CPUs related to the same policy, in case they use different
source of the freq scale.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
---
arch/arm64/kernel/topology.c | 54 ++++++++++++++++++++++++++++++++++--
1 file changed, 52 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 9317a618bb87..b68621b3c071 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -385,7 +385,7 @@ static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val,
struct cpufreq_policy *policy = data;
if (val == CPUFREQ_CREATE_POLICY)
- amu_fie_setup(policy->related_cpus);
+ amu_fie_setup(policy->cpus);
/*
* We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU
@@ -404,10 +404,60 @@ static struct notifier_block init_amu_fie_notifier = {
.notifier_call = init_amu_fie_callback,
};
+static int cpuhp_topology_online(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
+
+ /*
+ * If the online CPUs are not all AMU FIE CPUs or the new one is already
+ * an AMU FIE one, no need to set it.
+ */
+ if (!policy || !cpumask_available(amu_fie_cpus) ||
+ !cpumask_subset(policy->cpus, amu_fie_cpus) ||
+ cpumask_test_cpu(cpu, amu_fie_cpus))
+ return 0;
+
+ /*
+ * If the new online CPU cannot pass this check, all the CPUs related to
+ * the same policy should be clear from amu_fie_cpus mask, otherwise they
+ * may use different source of the freq scale.
+ */
+ if (!freq_counters_valid(cpu)) {
+ topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
+ policy->related_cpus);
+ cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
+ return 0;
+ }
+
+ cpumask_set_cpu(cpu, amu_fie_cpus);
+
+ topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
+
+ pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
+
+ return 0;
+}
+
static int __init init_amu_fie(void)
{
- return cpufreq_register_notifier(&init_amu_fie_notifier,
+ int ret;
+
+ ret = cpufreq_register_notifier(&init_amu_fie_notifier,
CPUFREQ_POLICY_NOTIFIER);
+ if (ret)
+ return ret;
+
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "arm64/topology:online",
+ cpuhp_topology_online,
+ NULL);
+ if (ret < 0) {
+ cpufreq_unregister_notifier(&init_amu_fie_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+ return ret;
+ }
+
+ return 0;
}
core_initcall(init_amu_fie);
--
2.33.0On Tue, Aug 05, 2025 at 05:33:30PM +0800, Lifeng Zheng wrote:
> When boot with maxcpu=1 restrict, and LPI(Low Power Idle States) is on,
> only CPU0 will go online. The support AMU flag of CPU0 will be set but the
> flags of other CPUs will not. This will cause AMU FIE set up fail for CPU0
> when it shares a cpufreq policy with other CPU(s). After that, when other
> CPUs are finally online and the support AMU flags of them are set, they'll
> never have a chance to set up AMU FIE, even though they're eligible.
>
> To solve this problem, the process of setting up AMU FIE needs to be
> modified as follows:
>
> 1. Set up AMU FIE only for the online CPUs.
>
> 2. Try to set up AMU FIE each time a CPU goes online and do the
> freq_counters_valid() check. If this check fails, clear scale freq source
> of all the CPUs related to the same policy, in case they use different
> source of the freq scale.
>
> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
> ---
> arch/arm64/kernel/topology.c | 54 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 52 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
> index 9317a618bb87..b68621b3c071 100644
> --- a/arch/arm64/kernel/topology.c
> +++ b/arch/arm64/kernel/topology.c
> @@ -385,7 +385,7 @@ static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val,
> struct cpufreq_policy *policy = data;
>
> if (val == CPUFREQ_CREATE_POLICY)
> - amu_fie_setup(policy->related_cpus);
> + amu_fie_setup(policy->cpus);
I think my previous comment still stands.
This will indeed set the AMU FIE support for online cpus.
Still, on each frequency change, arch_set_freq_scale will be called with
`related_cpus`, and that mask will be used to verify support for AMU counters,
and it will report there is none as 'related_cpus' won't be a subset of
`scale_freq_counters_mask`. As a consequence, new scale will be set, as seen by
the cpufreq. Now this will be corrected on next tick but it might cause
disruptions. So this change should also be applied to cpufreq - if feasible, or
at least be proven not to be an issue. Unless I am missing smth.
>
> /*
> * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU
> @@ -404,10 +404,60 @@ static struct notifier_block init_amu_fie_notifier = {
> .notifier_call = init_amu_fie_callback,
> };
>
> +static int cpuhp_topology_online(unsigned int cpu)
> +{
> + struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
> +
> + /*
> + * If the online CPUs are not all AMU FIE CPUs or the new one is already
> + * an AMU FIE one, no need to set it.
> + */
> + if (!policy || !cpumask_available(amu_fie_cpus) ||
> + !cpumask_subset(policy->cpus, amu_fie_cpus) ||
> + cpumask_test_cpu(cpu, amu_fie_cpus))
> + return 0;
This is getting rather cumbersome as the CPU that is coming online might belong
to a policy that is yet to be created. Both AMU FIE support, as well as cpufreq,
rely on dynamic hp state so, in theory, we cannot be certain that the cpufreq
callback will be fired first (although that seems to be the case).
If that does not happen, the policy will not exist, and as such given CPU
will not use AMUs for FIE. The problem might be hypothetical but it at least
deservers a comment I think.
Second problem is cpumask_available use: this might be the very fist CPU that
might potentially rely on AMUs for frequency invariance so that mask may not be
available yet. That does not mean AMUs setup should be skipped. Not just yet,
at least. Again more hypothetical.
BTW, there should be `amu_fie_cpu_supported'.
> +
> + /*
> + * If the new online CPU cannot pass this check, all the CPUs related to
> + * the same policy should be clear from amu_fie_cpus mask, otherwise they
> + * may use different source of the freq scale.
> + */
> + if (!freq_counters_valid(cpu)) {
> + topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
> + policy->related_cpus);
> + cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
I think it might deserve a warning as this probably should not happen.
---
BR
Beata
> + return 0;
> + }
> +
> + cpumask_set_cpu(cpu, amu_fie_cpus);
> +
> + topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
> +
> + pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
> +
> + return 0;
> +}
> +
> static int __init init_amu_fie(void)
> {
> - return cpufreq_register_notifier(&init_amu_fie_notifier,
> + int ret;
> +
> + ret = cpufreq_register_notifier(&init_amu_fie_notifier,
> CPUFREQ_POLICY_NOTIFIER);
> + if (ret)
> + return ret;
> +
> + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
> + "arm64/topology:online",
> + cpuhp_topology_online,
> + NULL);
> + if (ret < 0) {
> + cpufreq_unregister_notifier(&init_amu_fie_notifier,
> + CPUFREQ_POLICY_NOTIFIER);
> + return ret;
> + }
> +
> + return 0;
> }
> core_initcall(init_amu_fie);
>
> --
> 2.33.0
>
On 2025/8/6 17:55, Beata Michalska wrote:
> On Tue, Aug 05, 2025 at 05:33:30PM +0800, Lifeng Zheng wrote:
>> When boot with maxcpu=1 restrict, and LPI(Low Power Idle States) is on,
>> only CPU0 will go online. The support AMU flag of CPU0 will be set but the
>> flags of other CPUs will not. This will cause AMU FIE set up fail for CPU0
>> when it shares a cpufreq policy with other CPU(s). After that, when other
>> CPUs are finally online and the support AMU flags of them are set, they'll
>> never have a chance to set up AMU FIE, even though they're eligible.
>>
>> To solve this problem, the process of setting up AMU FIE needs to be
>> modified as follows:
>>
>> 1. Set up AMU FIE only for the online CPUs.
>>
>> 2. Try to set up AMU FIE each time a CPU goes online and do the
>> freq_counters_valid() check. If this check fails, clear scale freq source
>> of all the CPUs related to the same policy, in case they use different
>> source of the freq scale.
>>
>> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
>> ---
>> arch/arm64/kernel/topology.c | 54 ++++++++++++++++++++++++++++++++++--
>> 1 file changed, 52 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
>> index 9317a618bb87..b68621b3c071 100644
>> --- a/arch/arm64/kernel/topology.c
>> +++ b/arch/arm64/kernel/topology.c
>> @@ -385,7 +385,7 @@ static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val,
>> struct cpufreq_policy *policy = data;
>>
>> if (val == CPUFREQ_CREATE_POLICY)
>> - amu_fie_setup(policy->related_cpus);
>> + amu_fie_setup(policy->cpus);
> I think my previous comment still stands.
> This will indeed set the AMU FIE support for online cpus.
> Still, on each frequency change, arch_set_freq_scale will be called with
> `related_cpus`, and that mask will be used to verify support for AMU counters,
> and it will report there is none as 'related_cpus' won't be a subset of
> `scale_freq_counters_mask`. As a consequence, new scale will be set, as seen by
> the cpufreq. Now this will be corrected on next tick but it might cause
> disruptions. So this change should also be applied to cpufreq - if feasible, or
> at least be proven not to be an issue. Unless I am missing smth.
I know what you mean now. Yes, I think you are right, this change should
also be applied to cpufreq too. Thanks!
>>
>> /*
>> * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU
>> @@ -404,10 +404,60 @@ static struct notifier_block init_amu_fie_notifier = {
>> .notifier_call = init_amu_fie_callback,
>> };
>>
>> +static int cpuhp_topology_online(unsigned int cpu)
>> +{
>> + struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
>> +
>> + /*
>> + * If the online CPUs are not all AMU FIE CPUs or the new one is already
>> + * an AMU FIE one, no need to set it.
>> + */
>> + if (!policy || !cpumask_available(amu_fie_cpus) ||
>> + !cpumask_subset(policy->cpus, amu_fie_cpus) ||
>> + cpumask_test_cpu(cpu, amu_fie_cpus))
>> + return 0;
> This is getting rather cumbersome as the CPU that is coming online might belong
> to a policy that is yet to be created. Both AMU FIE support, as well as cpufreq,
> rely on dynamic hp state so, in theory, we cannot be certain that the cpufreq
> callback will be fired first (although that seems to be the case).
> If that does not happen, the policy will not exist, and as such given CPU
> will not use AMUs for FIE. The problem might be hypothetical but it at least
> deservers a comment I think.
Actually, this callback will always be fired before the cpufreq one,
because init_amu_fie() is called before any cpufreq driver init func (It
has to be, otherwise the init_amu_fie_notifier cannot be registered before
it is needed.). And the callback that is setup first will be called first
when online if rely on dynamic hp state. So in your hypothetical scenario,
yes, the policy will not exist and this funcion will do nothing. But that's
OK because the notifier callback will do what should be done when the
policy is being created.
> Second problem is cpumask_available use: this might be the very fist CPU that
> might potentially rely on AMUs for frequency invariance so that mask may not be
> available yet. That does not mean AMUs setup should be skipped. Not just yet,
> at least. Again more hypothetical.
Same, things will be done in the notifier callback when the policy is being
created.
> BTW, there should be `amu_fie_cpu_supported'.
Sorry, I can't see why it is needed. Could you explained further?
>> +
>> + /*
>> + * If the new online CPU cannot pass this check, all the CPUs related to
>> + * the same policy should be clear from amu_fie_cpus mask, otherwise they
>> + * may use different source of the freq scale.
>> + */
>> + if (!freq_counters_valid(cpu)) {
>> + topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
>> + policy->related_cpus);
>> + cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
> I think it might deserve a warning as this probably should not happen.
Yes, makes sense. Thanks!
>
> ---
> BR
> Beata
>> + return 0;
>> + }
>> +
>> + cpumask_set_cpu(cpu, amu_fie_cpus);
>> +
>> + topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
>> +
>> + pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
>> +
>> + return 0;
>> +}
>> +
>> static int __init init_amu_fie(void)
>> {
>> - return cpufreq_register_notifier(&init_amu_fie_notifier,
>> + int ret;
>> +
>> + ret = cpufreq_register_notifier(&init_amu_fie_notifier,
>> CPUFREQ_POLICY_NOTIFIER);
>> + if (ret)
>> + return ret;
>> +
>> + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
>> + "arm64/topology:online",
>> + cpuhp_topology_online,
>> + NULL);
>> + if (ret < 0) {
>> + cpufreq_unregister_notifier(&init_amu_fie_notifier,
>> + CPUFREQ_POLICY_NOTIFIER);
>> + return ret;
>> + }
>> +
>> + return 0;
>> }
>> core_initcall(init_amu_fie);
>>
>> --
>> 2.33.0
>>
>
On Wed, Aug 13, 2025 at 06:17:54PM +0800, zhenglifeng (A) wrote:
> On 2025/8/6 17:55, Beata Michalska wrote:
>
> > On Tue, Aug 05, 2025 at 05:33:30PM +0800, Lifeng Zheng wrote:
> >> When boot with maxcpu=1 restrict, and LPI(Low Power Idle States) is on,
> >> only CPU0 will go online. The support AMU flag of CPU0 will be set but the
> >> flags of other CPUs will not. This will cause AMU FIE set up fail for CPU0
> >> when it shares a cpufreq policy with other CPU(s). After that, when other
> >> CPUs are finally online and the support AMU flags of them are set, they'll
> >> never have a chance to set up AMU FIE, even though they're eligible.
> >>
> >> To solve this problem, the process of setting up AMU FIE needs to be
> >> modified as follows:
> >>
> >> 1. Set up AMU FIE only for the online CPUs.
> >>
> >> 2. Try to set up AMU FIE each time a CPU goes online and do the
> >> freq_counters_valid() check. If this check fails, clear scale freq source
> >> of all the CPUs related to the same policy, in case they use different
> >> source of the freq scale.
> >>
> >> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
> >> ---
> >> arch/arm64/kernel/topology.c | 54 ++++++++++++++++++++++++++++++++++--
> >> 1 file changed, 52 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
> >> index 9317a618bb87..b68621b3c071 100644
> >> --- a/arch/arm64/kernel/topology.c
> >> +++ b/arch/arm64/kernel/topology.c
> >> @@ -385,7 +385,7 @@ static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val,
> >> struct cpufreq_policy *policy = data;
> >>
> >> if (val == CPUFREQ_CREATE_POLICY)
> >> - amu_fie_setup(policy->related_cpus);
> >> + amu_fie_setup(policy->cpus);
> > I think my previous comment still stands.
> > This will indeed set the AMU FIE support for online cpus.
> > Still, on each frequency change, arch_set_freq_scale will be called with
> > `related_cpus`, and that mask will be used to verify support for AMU counters,
> > and it will report there is none as 'related_cpus' won't be a subset of
> > `scale_freq_counters_mask`. As a consequence, new scale will be set, as seen by
> > the cpufreq. Now this will be corrected on next tick but it might cause
> > disruptions. So this change should also be applied to cpufreq - if feasible, or
> > at least be proven not to be an issue. Unless I am missing smth.
>
> I know what you mean now. Yes, I think you are right, this change should
> also be applied to cpufreq too. Thanks!
>
> >>
> >> /*
> >> * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU
> >> @@ -404,10 +404,60 @@ static struct notifier_block init_amu_fie_notifier = {
> >> .notifier_call = init_amu_fie_callback,
> >> };
> >>
> >> +static int cpuhp_topology_online(unsigned int cpu)
> >> +{
> >> + struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
> >> +
> >> + /*
> >> + * If the online CPUs are not all AMU FIE CPUs or the new one is already
> >> + * an AMU FIE one, no need to set it.
> >> + */
> >> + if (!policy || !cpumask_available(amu_fie_cpus) ||
> >> + !cpumask_subset(policy->cpus, amu_fie_cpus) ||
> >> + cpumask_test_cpu(cpu, amu_fie_cpus))
> >> + return 0;
> > This is getting rather cumbersome as the CPU that is coming online might belong
> > to a policy that is yet to be created. Both AMU FIE support, as well as cpufreq,
> > rely on dynamic hp state so, in theory, we cannot be certain that the cpufreq
> > callback will be fired first (although that seems to be the case).
> > If that does not happen, the policy will not exist, and as such given CPU
> > will not use AMUs for FIE. The problem might be hypothetical but it at least
> > deservers a comment I think.
>
> Actually, this callback will always be fired before the cpufreq one,
> because init_amu_fie() is called before any cpufreq driver init func (It
> has to be, otherwise the init_amu_fie_notifier cannot be registered before
> it is needed.). And the callback that is setup first will be called first
> when online if rely on dynamic hp state. So in your hypothetical scenario,
> yes, the policy will not exist and this funcion will do nothing. But that's
> OK because the notifier callback will do what should be done when the
> policy is being created.
>
You are right, I definitely drifted away too much with this one.
> > Second problem is cpumask_available use: this might be the very fist CPU that
> > might potentially rely on AMUs for frequency invariance so that mask may not be
> > available yet. That does not mean AMUs setup should be skipped. Not just yet,
> > at least. Again more hypothetical.
>
> Same, things will be done in the notifier callback when the policy is being
> created.
>
> > BTW, there should be `amu_fie_cpu_supported'.
>
> Sorry, I can't see why it is needed. Could you explained further?
It covers the 'cpumask_available' and `cpumask_test_cpu` so I was thinking
your condition could look like:
if (!policy || amu_fie_cpu_supported(cpu) ||
!cpumask_subset(policy->cpus, amu_fie_cpus)
return 0
but that one will not cover all cases so feel free to ignore me.
---
BR
Beata
>
> >> +
> >> + /*
> >> + * If the new online CPU cannot pass this check, all the CPUs related to
> >> + * the same policy should be clear from amu_fie_cpus mask, otherwise they
> >> + * may use different source of the freq scale.
> >> + */
> >> + if (!freq_counters_valid(cpu)) {
> >> + topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
> >> + policy->related_cpus);
> >> + cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
> > I think it might deserve a warning as this probably should not happen.
>
> Yes, makes sense. Thanks!
>
> >
> > ---
> > BR
> > Beata
> >> + return 0;
> >> + }
> >> +
> >> + cpumask_set_cpu(cpu, amu_fie_cpus);
> >> +
> >> + topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
> >> +
> >> + pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> static int __init init_amu_fie(void)
> >> {
> >> - return cpufreq_register_notifier(&init_amu_fie_notifier,
> >> + int ret;
> >> +
> >> + ret = cpufreq_register_notifier(&init_amu_fie_notifier,
> >> CPUFREQ_POLICY_NOTIFIER);
> >> + if (ret)
> >> + return ret;
> >> +
> >> + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
> >> + "arm64/topology:online",
> >> + cpuhp_topology_online,
> >> + NULL);
> >> + if (ret < 0) {
> >> + cpufreq_unregister_notifier(&init_amu_fie_notifier,
> >> + CPUFREQ_POLICY_NOTIFIER);
> >> + return ret;
> >> + }
> >> +
> >> + return 0;
> >> }
> >> core_initcall(init_amu_fie);
> >>
> >> --
> >> 2.33.0
> >>
> >
>
Hi Lifeng,
kernel test robot noticed the following build errors:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on rafael-pm/linux-next rafael-pm/bleeding-edge arm/for-next arm/fixes kvmarm/next soc/for-next linus/master v6.16 next-20250806]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Lifeng-Zheng/arm64-topology-Set-scale-freq-source-only-for-the-CPUs-that-have-not-been-set-before/20250806-101537
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
patch link: https://lore.kernel.org/r/20250805093330.3715444-4-zhenglifeng1%40huawei.com
patch subject: [PATCH v3 3/3] arm64: topology: Setup AMU FIE for online CPUs only
config: arm64-randconfig-002-20250806 (https://download.01.org/0day-ci/archive/20250806/202508062127.qvRnTPvH-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 7b8dea265e72c3037b6b1e54d5ab51b7e14f328b)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250806/202508062127.qvRnTPvH-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508062127.qvRnTPvH-lkp@intel.com/
All errors (new ones prefixed by >>):
>> arch/arm64/kernel/topology.c:409:34: error: call to undeclared function 'cpufreq_cpu_get_raw_no_check'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
409 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
| ^
arch/arm64/kernel/topology.c:409:34: note: did you mean 'cpufreq_cpu_get_raw'?
include/linux/cpufreq.h:212:38: note: 'cpufreq_cpu_get_raw' declared here
212 | static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
| ^
>> arch/arm64/kernel/topology.c:409:25: error: incompatible integer to pointer conversion initializing 'struct cpufreq_policy *' with an expression of type 'int' [-Wint-conversion]
409 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 errors generated.
vim +/cpufreq_cpu_get_raw_no_check +409 arch/arm64/kernel/topology.c
406
407 static int cpuhp_topology_online(unsigned int cpu)
408 {
> 409 struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
410
411 /*
412 * If the online CPUs are not all AMU FIE CPUs or the new one is already
413 * an AMU FIE one, no need to set it.
414 */
415 if (!policy || !cpumask_available(amu_fie_cpus) ||
416 !cpumask_subset(policy->cpus, amu_fie_cpus) ||
417 cpumask_test_cpu(cpu, amu_fie_cpus))
418 return 0;
419
420 /*
421 * If the new online CPU cannot pass this check, all the CPUs related to
422 * the same policy should be clear from amu_fie_cpus mask, otherwise they
423 * may use different source of the freq scale.
424 */
425 if (!freq_counters_valid(cpu)) {
426 topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
427 policy->related_cpus);
428 cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
429 return 0;
430 }
431
432 cpumask_set_cpu(cpu, amu_fie_cpus);
433
434 topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
435
436 pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
437
438 return 0;
439 }
440
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Lifeng,
kernel test robot noticed the following build warnings:
[auto build test WARNING on arm64/for-next/core]
[also build test WARNING on rafael-pm/linux-next rafael-pm/bleeding-edge arm/for-next arm/fixes kvmarm/next soc/for-next linus/master v6.16 next-20250806]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Lifeng-Zheng/arm64-topology-Set-scale-freq-source-only-for-the-CPUs-that-have-not-been-set-before/20250806-101537
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
patch link: https://lore.kernel.org/r/20250805093330.3715444-4-zhenglifeng1%40huawei.com
patch subject: [PATCH v3 3/3] arm64: topology: Setup AMU FIE for online CPUs only
config: arm64-randconfig-003-20250806 (https://download.01.org/0day-ci/archive/20250806/202508062150.aKsrWjHB-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 9.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250806/202508062150.aKsrWjHB-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508062150.aKsrWjHB-lkp@intel.com/
All warnings (new ones prefixed by >>):
arch/arm64/kernel/topology.c: In function 'cpuhp_topology_online':
arch/arm64/kernel/topology.c:409:34: error: implicit declaration of function 'cpufreq_cpu_get_raw_no_check'; did you mean 'cpufreq_cpu_get_raw'? [-Werror=implicit-function-declaration]
409 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
| cpufreq_cpu_get_raw
>> arch/arm64/kernel/topology.c:409:34: warning: initialization of 'struct cpufreq_policy *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
cc1: some warnings being treated as errors
vim +409 arch/arm64/kernel/topology.c
406
407 static int cpuhp_topology_online(unsigned int cpu)
408 {
> 409 struct cpufreq_policy *policy = cpufreq_cpu_get_raw_no_check(cpu);
410
411 /*
412 * If the online CPUs are not all AMU FIE CPUs or the new one is already
413 * an AMU FIE one, no need to set it.
414 */
415 if (!policy || !cpumask_available(amu_fie_cpus) ||
416 !cpumask_subset(policy->cpus, amu_fie_cpus) ||
417 cpumask_test_cpu(cpu, amu_fie_cpus))
418 return 0;
419
420 /*
421 * If the new online CPU cannot pass this check, all the CPUs related to
422 * the same policy should be clear from amu_fie_cpus mask, otherwise they
423 * may use different source of the freq scale.
424 */
425 if (!freq_counters_valid(cpu)) {
426 topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_ARCH,
427 policy->related_cpus);
428 cpumask_andnot(amu_fie_cpus, amu_fie_cpus, policy->related_cpus);
429 return 0;
430 }
431
432 cpumask_set_cpu(cpu, amu_fie_cpus);
433
434 topology_set_scale_freq_source(&amu_sfd, cpumask_of(cpu));
435
436 pr_debug("CPU[%u]: counter will be used for FIE.", cpu);
437
438 return 0;
439 }
440
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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