From: "Rafael J. Wysocki" <[email protected]>
Add ->offline and ->online driver callbacksto to do the cleanup
before taking a CPU offline and to restore its working configuration
when it goes back online, respectively, to avoid invoking the ->init
callback on every CPU online which is quite a bit of unnecessary
overhead.
Define ->offline and ->online so that they can be used in the
passive as well as in the active mode and because ->offline will
do the majority of ->stop_cpu work, the passive mode does not
need that callback any more, so drop it.
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/cpufreq/intel_pstate.c | 38 ++++++++++++++++++++++++++++------
1 file changed, 32 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 3d18934fa975..aca0587b176f 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2297,28 +2297,51 @@ static int intel_pstate_verify_policy(struct cpufreq_policy_data *policy)
return 0;
}
-static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy)
+static int intel_pstate_cpu_offline(struct cpufreq_policy *policy)
{
+ pr_debug("CPU %d going offline\n", policy->cpu);
+
+ intel_pstate_exit_perf_limits(policy);
+
+ /*
+ * If the CPU is an SMT thread and it goes offline with the performance
+ * settings different from the minimum, it will prevent its sibling
+ * from getting to lower performance levels, so force the minimum
+ * performance on CPU offline to prevent that form happening.
+ */
if (hwp_active)
intel_pstate_hwp_force_min_perf(policy->cpu);
else
intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]);
+
+ return 0;
+}
+
+static int intel_pstate_cpu_online(struct cpufreq_policy *policy)
+{
+ pr_debug("CPU %d going online\n", policy->cpu);
+
+ intel_pstate_init_acpi_perf_limits(policy);
+
+ if (hwp_active)
+ wrmsrl_on_cpu(policy->cpu, MSR_HWP_REQUEST,
+ all_cpu_data[policy->cpu]->hwp_req_cached);
+
+ return 0;
}
static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
{
- pr_debug("CPU %d exiting\n", policy->cpu);
+ pr_debug("CPU %d stopping\n", policy->cpu);
intel_pstate_clear_update_util_hook(policy->cpu);
if (hwp_active)
intel_pstate_hwp_save_state(policy);
-
- intel_cpufreq_stop_cpu(policy);
}
static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
{
- intel_pstate_exit_perf_limits(policy);
+ pr_debug("CPU %d exiting\n", policy->cpu);
policy->fast_switch_possible = false;
@@ -2398,6 +2421,8 @@ static struct cpufreq_driver intel_pstate = {
.init = intel_pstate_cpu_init,
.exit = intel_pstate_cpu_exit,
.stop_cpu = intel_pstate_stop_cpu,
+ .offline = intel_pstate_cpu_offline,
+ .online = intel_pstate_cpu_online,
.update_limits = intel_pstate_update_limits,
.name = "intel_pstate",
};
@@ -2652,7 +2677,8 @@ static struct cpufreq_driver intel_cpufreq = {
.fast_switch = intel_cpufreq_fast_switch,
.init = intel_cpufreq_cpu_init,
.exit = intel_cpufreq_cpu_exit,
- .stop_cpu = intel_cpufreq_stop_cpu,
+ .offline = intel_pstate_cpu_offline,
+ .online = intel_pstate_cpu_online,
.update_limits = intel_pstate_update_limits,
.name = "intel_cpufreq",
};
--
2.26.2
Hi Rafael,
Just annoying typo type feedback.
On 2020.08.20 09:38 Rafael J. Wysocki wrote:
>
> From: "Rafael J. Wysocki" <[email protected]>
>
> Add ->offline and ->online driver callbacksto to do the cleanup
"to to" and suggest this:
Add ->offline and ->online driver callbacks to cleanup
> before taking a CPU offline and to restore its working configuration
> when it goes back online, respectively, to avoid invoking the ->init
> callback on every CPU online which is quite a bit of unnecessary
> overhead.
>
> Define ->offline and ->online so that they can be used in the
> passive as well as in the active mode and because ->offline will
passive mode
> do the majority of ->stop_cpu work, the passive mode does not
> need that callback any more, so drop it.
>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
> drivers/cpufreq/intel_pstate.c | 38 ++++++++++++++++++++++++++++------
> 1 file changed, 32 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 3d18934fa975..aca0587b176f 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -2297,28 +2297,51 @@ static int intel_pstate_verify_policy(struct cpufreq_policy_data *policy)
> return 0;
> }
>
> -static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy)
> +static int intel_pstate_cpu_offline(struct cpufreq_policy *policy)
> {
> + pr_debug("CPU %d going offline\n", policy->cpu);
> +
> + intel_pstate_exit_perf_limits(policy);
> +
> + /*
> + * If the CPU is an SMT thread and it goes offline with the performance
> + * settings different from the minimum, it will prevent its sibling
> + * from getting to lower performance levels, so force the minimum
> + * performance on CPU offline to prevent that form happening.
form/from
> + */
> if (hwp_active)
> intel_pstate_hwp_force_min_perf(policy->cpu);
> else
> intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]);
> +
> + return 0;
> +}
> +
> +static int intel_pstate_cpu_online(struct cpufreq_policy *policy)
> +{
> + pr_debug("CPU %d going online\n", policy->cpu);
> +
> + intel_pstate_init_acpi_perf_limits(policy);
> +
> + if (hwp_active)
> + wrmsrl_on_cpu(policy->cpu, MSR_HWP_REQUEST,
> + all_cpu_data[policy->cpu]->hwp_req_cached);
> +
> + return 0;
> }
>
> static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
> {
> - pr_debug("CPU %d exiting\n", policy->cpu);
> + pr_debug("CPU %d stopping\n", policy->cpu);
>
> intel_pstate_clear_update_util_hook(policy->cpu);
> if (hwp_active)
> intel_pstate_hwp_save_state(policy);
> -
> - intel_cpufreq_stop_cpu(policy);
> }
>
> static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
> {
> - intel_pstate_exit_perf_limits(policy);
> + pr_debug("CPU %d exiting\n", policy->cpu);
>
> policy->fast_switch_possible = false;
>
> @@ -2398,6 +2421,8 @@ static struct cpufreq_driver intel_pstate = {
> .init = intel_pstate_cpu_init,
> .exit = intel_pstate_cpu_exit,
> .stop_cpu = intel_pstate_stop_cpu,
> + .offline = intel_pstate_cpu_offline,
> + .online = intel_pstate_cpu_online,
> .update_limits = intel_pstate_update_limits,
> .name = "intel_pstate",
> };
> @@ -2652,7 +2677,8 @@ static struct cpufreq_driver intel_cpufreq = {
> .fast_switch = intel_cpufreq_fast_switch,
> .init = intel_cpufreq_cpu_init,
> .exit = intel_cpufreq_cpu_exit,
> - .stop_cpu = intel_cpufreq_stop_cpu,
> + .offline = intel_pstate_cpu_offline,
> + .online = intel_pstate_cpu_online,
> .update_limits = intel_pstate_update_limits,
> .name = "intel_cpufreq",
> };
> --
> 2.26.2
>
>
On Saturday, August 22, 2020 2:47:16 AM CEST Doug Smythies wrote:
> Hi Rafael,
>
> Just annoying typo type feedback.
Thanks!
Please find a corrected patch below.
Cheers!
---
From: Rafael J. Wysocki <[email protected]>
Subject: [PATCH] cpufreq: intel_pstate: Add ->offline and ->online callbacks
Add ->offline and ->online driver callbacks to prepare for taking a
CPU offline and to restore its working configuration when it goes
back online, respectively, to avoid invoking the ->init callback on
every CPU online which is quite a bit of unnecessary overhead.
Define ->offline and ->online so that they can be used in the
passive mode as well as in the active mode and because ->offline
will do the majority of ->stop_cpu work, the passive mode does
not need that callback any more, so drop it.
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/cpufreq/intel_pstate.c | 38 ++++++++++++++++++++++++++++++++------
1 file changed, 32 insertions(+), 6 deletions(-)
Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -2297,28 +2297,51 @@ static int intel_pstate_verify_policy(st
return 0;
}
-static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy)
+static int intel_pstate_cpu_offline(struct cpufreq_policy *policy)
{
+ pr_debug("CPU %d going offline\n", policy->cpu);
+
+ intel_pstate_exit_perf_limits(policy);
+
+ /*
+ * If the CPU is an SMT thread and it goes offline with the performance
+ * settings different from the minimum, it will prevent its sibling
+ * from getting to lower performance levels, so force the minimum
+ * performance on CPU offline to prevent that from happening.
+ */
if (hwp_active)
intel_pstate_hwp_force_min_perf(policy->cpu);
else
intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]);
+
+ return 0;
+}
+
+static int intel_pstate_cpu_online(struct cpufreq_policy *policy)
+{
+ pr_debug("CPU %d going online\n", policy->cpu);
+
+ intel_pstate_init_acpi_perf_limits(policy);
+
+ if (hwp_active)
+ wrmsrl_on_cpu(policy->cpu, MSR_HWP_REQUEST,
+ all_cpu_data[policy->cpu]->hwp_req_cached);
+
+ return 0;
}
static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
{
- pr_debug("CPU %d exiting\n", policy->cpu);
+ pr_debug("CPU %d stopping\n", policy->cpu);
intel_pstate_clear_update_util_hook(policy->cpu);
if (hwp_active)
intel_pstate_hwp_save_state(policy);
-
- intel_cpufreq_stop_cpu(policy);
}
static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
{
- intel_pstate_exit_perf_limits(policy);
+ pr_debug("CPU %d exiting\n", policy->cpu);
policy->fast_switch_possible = false;
@@ -2398,6 +2421,8 @@ static struct cpufreq_driver intel_pstat
.init = intel_pstate_cpu_init,
.exit = intel_pstate_cpu_exit,
.stop_cpu = intel_pstate_stop_cpu,
+ .offline = intel_pstate_cpu_offline,
+ .online = intel_pstate_cpu_online,
.update_limits = intel_pstate_update_limits,
.name = "intel_pstate",
};
@@ -2652,7 +2677,8 @@ static struct cpufreq_driver intel_cpufr
.fast_switch = intel_cpufreq_fast_switch,
.init = intel_cpufreq_cpu_init,
.exit = intel_cpufreq_cpu_exit,
- .stop_cpu = intel_cpufreq_stop_cpu,
+ .offline = intel_pstate_cpu_offline,
+ .online = intel_pstate_cpu_online,
.update_limits = intel_pstate_update_limits,
.name = "intel_cpufreq",
};