Add a new sysfs attribute file to support per CPU frequency boost
control, allowing individual CPUs to enable or disable CPB separately.
The new sysfs attribute file is located at below path,
`/sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb`,
where `X` represents the CPU number.
To disable CPB for a specific CPU, you can use the following command:
$ sudo bash -c "echo 0 > /sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb"
After disabling CPB, the CPU frequency will no longer boost beyond
the base frequency for that particular CPU.
for example:
----------------------------------------------------------------------
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
0 0 0 0 0:0:0:0 yes 4208.0000 400.0000 1666.7740
1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 400.0000
----------------------------------------------------------------------
$ sudo bash -c "echo 0 > /sys/devices/system/cpu/cpu0/cpufreq/amd_pstate_boost_cpb"
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
0 0 0 0 0:0:0:0 yes 3501.0000 400.0000 4154.3140
1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 400.0000
Please be aware that modifying the global variable
`amd_pstate_global_params.cpb_boost` will overwrite the individual CPU settings.
Signed-off-by: Perry Yuan <[email protected]>
---
drivers/cpufreq/amd-pstate.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 11bce2c1db32..44531711a5fa 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1371,6 +1371,30 @@ static int amd_pstate_cpu_boost(int cpu, bool state)
return ret < 0 ? ret : 0;
}
+static ssize_t show_amd_pstate_boost_cpb(struct cpufreq_policy *policy, char *buf)
+{
+ struct amd_cpudata *cpudata = policy->driver_data;
+ bool boost_val;
+
+ boost_val = READ_ONCE(cpudata->boost_state);
+
+ return sysfs_emit(buf, "%u\n", boost_val);
+}
+
+static ssize_t store_amd_pstate_boost_cpb(
+ struct cpufreq_policy *policy, const char *buf, size_t count)
+{
+ bool boost_val;
+ int ret;
+
+ if (sscanf(buf, "%d", &boost_val) != 1)
+ return -EINVAL;
+
+ ret = amd_pstate_cpu_boost(policy->cpu, boost_val);
+
+ return ret < 0 ? ret : count;
+}
+
static ssize_t cpb_boost_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1416,6 +1440,7 @@ cpufreq_freq_attr_ro(amd_pstate_prefcore_ranking);
cpufreq_freq_attr_ro(amd_pstate_hw_prefcore);
cpufreq_freq_attr_rw(energy_performance_preference);
cpufreq_freq_attr_ro(energy_performance_available_preferences);
+cpufreq_freq_attr_rw(amd_pstate_boost_cpb);
static DEVICE_ATTR_RW(status);
static DEVICE_ATTR_RO(prefcore);
static DEVICE_ATTR_RW(cpb_boost);
@@ -1426,6 +1451,7 @@ static struct freq_attr *amd_pstate_attr[] = {
&amd_pstate_highest_perf,
&amd_pstate_prefcore_ranking,
&amd_pstate_hw_prefcore,
+ &amd_pstate_boost_cpb,
NULL,
};
@@ -1437,6 +1463,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
&amd_pstate_hw_prefcore,
&energy_performance_preference,
&energy_performance_available_preferences,
+ &amd_pstate_boost_cpb,
NULL,
};
--
2.34.1
On 5/6/2024 5:19 AM, Perry Yuan wrote:
> Add a new sysfs attribute file to support per CPU frequency boost
> control, allowing individual CPUs to enable or disable CPB separately.
I don't think it should be "both" global and per CPU. It should be one
or the other (and I think per CPU is better).
>
> The new sysfs attribute file is located at below path,
> `/sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb`,
> where `X` represents the CPU number.
>
> To disable CPB for a specific CPU, you can use the following command:
> $ sudo bash -c "echo 0 > /sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb"
>
> After disabling CPB, the CPU frequency will no longer boost beyond
> the base frequency for that particular CPU.
>
> for example:
> ----------------------------------------------------------------------
> CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
> 0 0 0 0 0:0:0:0 yes 4208.0000 400.0000 1666.7740
> 1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 400.0000
>
> ----------------------------------------------------------------------
> $ sudo bash -c "echo 0 > /sys/devices/system/cpu/cpu0/cpufreq/amd_pstate_boost_cpb"
>
> CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
> 0 0 0 0 0:0:0:0 yes 3501.0000 400.0000 4154.3140
> 1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 400.0000
>
> Please be aware that modifying the global variable
> `amd_pstate_global_params.cpb_boost` will overwrite the individual CPU settings.
>
> Signed-off-by: Perry Yuan <[email protected]>
> ---
> drivers/cpufreq/amd-pstate.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 11bce2c1db32..44531711a5fa 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1371,6 +1371,30 @@ static int amd_pstate_cpu_boost(int cpu, bool state)
> return ret < 0 ? ret : 0;
> }
>
> +static ssize_t show_amd_pstate_boost_cpb(struct cpufreq_policy *policy, char *buf)
> +{
> + struct amd_cpudata *cpudata = policy->driver_data;
> + bool boost_val;
> +
> + boost_val = READ_ONCE(cpudata->boost_state);
> +
> + return sysfs_emit(buf, "%u\n", boost_val);
> +}
> +
> +static ssize_t store_amd_pstate_boost_cpb(
> + struct cpufreq_policy *policy, const char *buf, size_t count)
> +{
> + bool boost_val;
> + int ret;
> +
> + if (sscanf(buf, "%d", &boost_val) != 1)
> + return -EINVAL;
> +
> + ret = amd_pstate_cpu_boost(policy->cpu, boost_val);
> +
> + return ret < 0 ? ret : count;
> +}
> +
> static ssize_t cpb_boost_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -1416,6 +1440,7 @@ cpufreq_freq_attr_ro(amd_pstate_prefcore_ranking);
> cpufreq_freq_attr_ro(amd_pstate_hw_prefcore);
> cpufreq_freq_attr_rw(energy_performance_preference);
> cpufreq_freq_attr_ro(energy_performance_available_preferences);
> +cpufreq_freq_attr_rw(amd_pstate_boost_cpb);
> static DEVICE_ATTR_RW(status);
> static DEVICE_ATTR_RO(prefcore);
> static DEVICE_ATTR_RW(cpb_boost);
> @@ -1426,6 +1451,7 @@ static struct freq_attr *amd_pstate_attr[] = {
> &amd_pstate_highest_perf,
> &amd_pstate_prefcore_ranking,
> &amd_pstate_hw_prefcore,
> + &amd_pstate_boost_cpb,
> NULL,
> };
>
> @@ -1437,6 +1463,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
> &amd_pstate_hw_prefcore,
> &energy_performance_preference,
> &energy_performance_available_preferences,
> + &amd_pstate_boost_cpb,
> NULL,
> };
>