cpufreq: intel_pstate: Configurable algorithm to get target pstate
Target systems using different cpus have different power and performance
requirements. They may use different algorithms to get the next P-state
based on their power or performance preference.
For example, power-constrained systems may not want to use
high-performance P-states as aggressively as a full-size desktop or a
server platform. A server platform may want to run close to the max to
achieve better performance, while laptop-like systems may prefer
sacrificing performance for longer battery lifes.
For the above reasons, modify intel_pstate to allow the target P-state
selection algorithm to be depend on the CPU ID.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Philippe Longepe <philippe.longepe@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 4d07cbd..ff58029 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -66,6 +66,7 @@
struct sample {
int32_t core_pct_busy;
+ int32_t busy_scaled;
u64 aperf;
u64 mperf;
u64 tsc;
@@ -133,6 +134,7 @@
int (*get_scaling)(void);
void (*set)(struct cpudata*, int pstate);
void (*get_vid)(struct cpudata *);
+ int32_t (*get_target_pstate)(struct cpudata *);
};
struct cpu_defaults {
@@ -140,6 +142,8 @@
struct pstate_funcs funcs;
};
+static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu);
+
static struct pstate_adjust_policy pid_params;
static struct pstate_funcs pstate_funcs;
static int hwp_active;
@@ -738,6 +742,7 @@
.get_turbo = core_get_turbo_pstate,
.get_scaling = core_get_scaling,
.set = core_set_pstate,
+ .get_target_pstate = get_target_pstate_use_performance,
},
};
@@ -758,6 +763,7 @@
.set = atom_set_pstate,
.get_scaling = silvermont_get_scaling,
.get_vid = atom_get_vid,
+ .get_target_pstate = get_target_pstate_use_performance,
},
};
@@ -778,6 +784,7 @@
.set = atom_set_pstate,
.get_scaling = airmont_get_scaling,
.get_vid = atom_get_vid,
+ .get_target_pstate = get_target_pstate_use_performance,
},
};
@@ -797,6 +804,7 @@
.get_turbo = knl_get_turbo_pstate,
.get_scaling = core_get_scaling,
.set = core_set_pstate,
+ .get_target_pstate = get_target_pstate_use_performance,
},
};
@@ -922,7 +930,7 @@
mod_timer_pinned(&cpu->timer, jiffies + delay);
}
-static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
+static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
{
int32_t core_busy, max_pstate, current_pstate, sample_ratio;
s64 duration_us;
@@ -960,30 +968,24 @@
core_busy = mul_fp(core_busy, sample_ratio);
}
- return core_busy;
+ cpu->sample.busy_scaled = core_busy;
+ return cpu->pstate.current_pstate - pid_calc(&cpu->pid, core_busy);
}
static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
{
- int32_t busy_scaled;
- struct _pid *pid;
- signed int ctl;
- int from;
+ int from, target_pstate;
struct sample *sample;
from = cpu->pstate.current_pstate;
- pid = &cpu->pid;
- busy_scaled = intel_pstate_get_scaled_busy(cpu);
+ target_pstate = pstate_funcs.get_target_pstate(cpu);
- ctl = pid_calc(pid, busy_scaled);
-
- /* Negative values of ctl increase the pstate and vice versa */
- intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl, true);
+ intel_pstate_set_pstate(cpu, target_pstate, true);
sample = &cpu->sample;
trace_pstate_sample(fp_toint(sample->core_pct_busy),
- fp_toint(busy_scaled),
+ fp_toint(sample->busy_scaled),
from,
cpu->pstate.current_pstate,
sample->mperf,
@@ -1237,6 +1239,8 @@
pstate_funcs.get_scaling = funcs->get_scaling;
pstate_funcs.set = funcs->set;
pstate_funcs.get_vid = funcs->get_vid;
+ pstate_funcs.get_target_pstate = funcs->get_target_pstate;
+
}
#if IS_ENABLED(CONFIG_ACPI)