[PATCH] cpufreq: intel_pstate: Drop boost_iowait flag

From: Rafael J. Wysocki
Date: Tue Oct 18 2016 - 20:46:49 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

The "IOwait boosting" mechanism is only used by the
get_target_pstate_use_cpu_load() governor function and the
boost_iowait flag in pid_params is always set when that function
is in use (and it is never set otherwise). This means that the
boost_iowait flag is in fact redundant and may be dropped.

For this reason, replace the boost_iowait flag check in
intel_pstate_update_util() with an equivalent check against
pstate_funcs.get_target_pstate and drop that flag.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 7 +------
1 file changed, 1 insertion(+), 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
@@ -233,7 +233,6 @@ 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.
*/
@@ -245,7 +244,6 @@ struct pstate_adjust_policy {
int p_gain_pct;
int d_gain_pct;
int i_gain_pct;
- bool boost_iowait;
};

/**
@@ -1043,7 +1041,6 @@ static const struct cpu_defaults silverm
.p_gain_pct = 14,
.d_gain_pct = 0,
.i_gain_pct = 4,
- .boost_iowait = true,
},
.funcs = {
.get_max = atom_get_max_pstate,
@@ -1065,7 +1062,6 @@ static const struct cpu_defaults airmont
.p_gain_pct = 14,
.d_gain_pct = 0,
.i_gain_pct = 4,
- .boost_iowait = true,
},
.funcs = {
.get_max = atom_get_max_pstate,
@@ -1107,7 +1103,6 @@ static const struct cpu_defaults bxt_par
.p_gain_pct = 14,
.d_gain_pct = 0,
.i_gain_pct = 4,
- .boost_iowait = true,
},
.funcs = {
.get_max = core_get_max_pstate,
@@ -1346,7 +1341,7 @@ static void intel_pstate_update_util(str
struct cpudata *cpu = container_of(data, struct cpudata, update_util);
u64 delta_ns;

- if (pid_params.boost_iowait) {
+ if (pstate_funcs.get_target_pstate == get_target_pstate_use_cpu_load) {
if (flags & SCHED_CPUFREQ_IOWAIT) {
cpu->iowait_boost = int_tofp(1);
} else if (cpu->iowait_boost) {