cpufreq: intel_pstate: Use IOWAIT flag in Atom algorithm
Modify the P-state selection algorithm for Atom processors to use the new SCHED_CPUFREQ_IOWAIT flag instead of the questionable get_cpu_iowait_time_us() function. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
parent
21ca6d2c52
commit
09c448d3c6
|
@ -181,6 +181,8 @@ struct _pid {
|
|||
* @cpu: CPU number for this instance data
|
||||
* @update_util: CPUFreq utility callback information
|
||||
* @update_util_set: CPUFreq utility callback is set
|
||||
* @iowait_boost: iowait-related boost fraction
|
||||
* @last_update: Time of the last update.
|
||||
* @pstate: Stores P state limits for this CPU
|
||||
* @vid: Stores VID limits for this CPU
|
||||
* @pid: Stores PID parameters for this CPU
|
||||
|
@ -206,6 +208,7 @@ struct cpudata {
|
|||
struct vid_data vid;
|
||||
struct _pid pid;
|
||||
|
||||
u64 last_update;
|
||||
u64 last_sample_time;
|
||||
u64 prev_aperf;
|
||||
u64 prev_mperf;
|
||||
|
@ -216,6 +219,7 @@ struct cpudata {
|
|||
struct acpi_processor_performance acpi_perf_data;
|
||||
bool valid_pss_table;
|
||||
#endif
|
||||
unsigned int iowait_boost;
|
||||
};
|
||||
|
||||
static struct cpudata **all_cpu_data;
|
||||
|
@ -229,6 +233,7 @@ static struct cpudata **all_cpu_data;
|
|||
* @p_gain_pct: PID proportional gain
|
||||
* @i_gain_pct: PID integral gain
|
||||
* @d_gain_pct: PID derivative gain
|
||||
* @boost_iowait: Whether or not to use iowait boosting.
|
||||
*
|
||||
* Stores per CPU model static PID configuration data.
|
||||
*/
|
||||
|
@ -240,6 +245,7 @@ struct pstate_adjust_policy {
|
|||
int p_gain_pct;
|
||||
int d_gain_pct;
|
||||
int i_gain_pct;
|
||||
bool boost_iowait;
|
||||
};
|
||||
|
||||
/**
|
||||
|
@ -1037,6 +1043,7 @@ static struct cpu_defaults silvermont_params = {
|
|||
.p_gain_pct = 14,
|
||||
.d_gain_pct = 0,
|
||||
.i_gain_pct = 4,
|
||||
.boost_iowait = true,
|
||||
},
|
||||
.funcs = {
|
||||
.get_max = atom_get_max_pstate,
|
||||
|
@ -1058,6 +1065,7 @@ static struct cpu_defaults airmont_params = {
|
|||
.p_gain_pct = 14,
|
||||
.d_gain_pct = 0,
|
||||
.i_gain_pct = 4,
|
||||
.boost_iowait = true,
|
||||
},
|
||||
.funcs = {
|
||||
.get_max = atom_get_max_pstate,
|
||||
|
@ -1099,6 +1107,7 @@ static struct cpu_defaults bxt_params = {
|
|||
.p_gain_pct = 14,
|
||||
.d_gain_pct = 0,
|
||||
.i_gain_pct = 4,
|
||||
.boost_iowait = true,
|
||||
},
|
||||
.funcs = {
|
||||
.get_max = core_get_max_pstate,
|
||||
|
@ -1222,36 +1231,18 @@ static inline int32_t get_avg_pstate(struct cpudata *cpu)
|
|||
static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
|
||||
{
|
||||
struct sample *sample = &cpu->sample;
|
||||
u64 cummulative_iowait, delta_iowait_us;
|
||||
u64 delta_iowait_mperf;
|
||||
u64 mperf, now;
|
||||
int32_t cpu_load;
|
||||
int32_t busy_frac, boost;
|
||||
|
||||
cummulative_iowait = get_cpu_iowait_time_us(cpu->cpu, &now);
|
||||
busy_frac = div_fp(sample->mperf, sample->tsc);
|
||||
|
||||
/*
|
||||
* Convert iowait time into number of IO cycles spent at max_freq.
|
||||
* IO is considered as busy only for the cpu_load algorithm. For
|
||||
* performance this is not needed since we always try to reach the
|
||||
* maximum P-State, so we are already boosting the IOs.
|
||||
*/
|
||||
delta_iowait_us = cummulative_iowait - cpu->prev_cummulative_iowait;
|
||||
delta_iowait_mperf = div64_u64(delta_iowait_us * cpu->pstate.scaling *
|
||||
cpu->pstate.max_pstate, MSEC_PER_SEC);
|
||||
boost = cpu->iowait_boost;
|
||||
cpu->iowait_boost >>= 1;
|
||||
|
||||
mperf = cpu->sample.mperf + delta_iowait_mperf;
|
||||
cpu->prev_cummulative_iowait = cummulative_iowait;
|
||||
if (busy_frac < boost)
|
||||
busy_frac = boost;
|
||||
|
||||
/*
|
||||
* The load can be estimated as the ratio of the mperf counter
|
||||
* running at a constant frequency during active periods
|
||||
* (C0) and the time stamp counter running at the same frequency
|
||||
* also during C-states.
|
||||
*/
|
||||
cpu_load = div64_u64(int_tofp(100) * mperf, sample->tsc);
|
||||
cpu->sample.busy_scaled = cpu_load;
|
||||
|
||||
return get_avg_pstate(cpu) - pid_calc(&cpu->pid, cpu_load);
|
||||
sample->busy_scaled = busy_frac * 100;
|
||||
return get_avg_pstate(cpu) - pid_calc(&cpu->pid, sample->busy_scaled);
|
||||
}
|
||||
|
||||
static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
|
||||
|
@ -1332,8 +1323,21 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time,
|
|||
unsigned int flags)
|
||||
{
|
||||
struct cpudata *cpu = container_of(data, struct cpudata, update_util);
|
||||
u64 delta_ns = time - cpu->sample.time;
|
||||
u64 delta_ns;
|
||||
|
||||
if (pid_params.boost_iowait) {
|
||||
if (flags & SCHED_CPUFREQ_IOWAIT) {
|
||||
cpu->iowait_boost = int_tofp(1);
|
||||
} else if (cpu->iowait_boost) {
|
||||
/* Clear iowait_boost if the CPU may have been idle. */
|
||||
delta_ns = time - cpu->last_update;
|
||||
if (delta_ns > TICK_NSEC)
|
||||
cpu->iowait_boost = 0;
|
||||
}
|
||||
cpu->last_update = time;
|
||||
}
|
||||
|
||||
delta_ns = time - cpu->sample.time;
|
||||
if ((s64)delta_ns >= pid_params.sample_rate_ns) {
|
||||
bool sample_taken = intel_pstate_sample(cpu, time);
|
||||
|
||||
|
|
Loading…
Reference in a new issue