sched: eliminate sched_freq_account_wait_time knob

Kill unused scheduler knob sched_freq_account_wait_time.

Change-Id: Ib74123ebd69dfa3f86cf7335099f50c12a6e93c3
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>

Documentation/scheduler/sched-zone.txt

@@ -920,7 +920,7 @@ The above counters are resued for nt_curr_runnable_sum and
 nt_prev_runnable_sum.
 
 "cpu demand" of a task includes its execution time and can also include its
-wait time. 'sched_freq_account_wait_time' tunable controls whether task's wait
+wait time. 'SCHED_FREQ_ACCOUNT_WAIT_TIME' controls whether task's wait
 time is included in its 'curr_window' and 'prev_window' counters or not.
 
 Needless to say, curr_runnable_sum counter of a cpu is derived from curr_window
@@ -934,7 +934,7 @@ PICK_NEXT_TASK
 	This represents beginning of execution for a task. Provided the task
 	refers to a non-idle task, a portion of task's wait time that
 	corresponds to the current window being tracked on a cpu is added to
-	task's curr_window counter, provided sched_freq_account_wait_time is
+	task's curr_window counter, provided SCHED_FREQ_ACCOUNT_WAIT_TIME is
 	set. The same quantum is also added to cpu's curr_runnable_sum counter.
 	The remaining portion, which corresponds to task's wait time in previous
 	window is added to task's prev_window and cpu's prev_runnable_sum
@@ -969,7 +969,7 @@ TASK_MIGRATE
 	this event reflects actions taken under PICK_NEXT_TASK (i.e its
 	wait time is added to task's curr/prev_window counters as well
 	as src_cpu's curr/prev_runnable_sum counters, provided
-	sched_freq_account_wait_time tunable is non-zero). After that update,
+	SCHED_FREQ_ACCOUNT_WAIT_TIME is non-zero). After that update,
 	src_cpu's curr_runnable_sum is reduced by task's curr_window value
 	and dst_cpu's curr_runnable_sum is increased by task's curr_window
 	value, provided sched_migration_fixup = 1. Similarly, src_cpu's
@@ -1113,17 +1113,7 @@ tracking mechanism maintains per task. If default values are used for
 both this and sched_ravg_window then a total of 50ms of task history
 would be maintained in 5 10ms windows.
 
-*** 7.11 sched_freq_account_wait_time
+*** 7.11 sched_migration_fixup
-
-Appears at: /proc/sys/kernel/sched_freq_account_wait_time
-
-Default value: 0
-
-This controls whether a task's wait time is accounted in its curr_window and
-prev_window attributes and thus in a cpu's curr_runnable_sum and
-prev_runnable_sum counters.
-
-*** 7.12 sched_migration_fixup
 
 Appears at: /proc/sys/kernel/sched_migration_fixup
 
@@ -1132,7 +1122,7 @@ Default value: 1
 This controls whether a cpu's busy time counters are adjusted during task
 migration.
 
-*** 7.13 sched_freq_inc_notify
+*** 7.12 sched_freq_inc_notify
 
 Appears at: /proc/sys/kernel/sched_freq_inc_notify
 
@@ -1144,7 +1134,7 @@ exceeds sched_freq_inc_notify, where freq_required is the frequency calculated
 by scheduler to meet current task demand. Note that sched_freq_inc_notify is
 specified in kHz units.
 
-*** 7.14 sched_freq_dec_notify
+*** 7.13 sched_freq_dec_notify
 
 Appears at: /proc/sys/kernel/sched_freq_dec_notify
 
@@ -1157,7 +1147,7 @@ exceeds sched_freq_dec_notify, where freq_required is the frequency calculated
 by scheduler to meet current task demand. Note that sched_freq_dec_notify is
 specified in kHz units.
 
-** 7.15 sched_heavy_task
+*** 7.14 sched_heavy_task
 
 Appears at: /proc/sys/kernel/sched_heavy_task
 
@@ -1169,7 +1159,7 @@ comparison. Scheduler will request a raise in cpu frequency when heavy tasks
 wakeup after at least one window of sleep, where window size is defined by
 sched_ravg_window. Value 0 will disable this feature.
 
-*** 7.16 sched_cpu_high_irqload
+*** 7.15 sched_cpu_high_irqload
 
 Appears at: /proc/sys/kernel/sched_cpu_high_irqload
 
@@ -1187,7 +1177,7 @@ longer eligible for placement. This will affect the task placement logic
 described above, causing the scheduler to try and steer tasks away from
 the CPU.
 
-** 7.17 cpu.upmigrate_discourage
+*** 7.16 cpu.upmigrate_discourage
 
 Default value : 0
 
@@ -1203,7 +1193,7 @@ overcommitted scenario. See notes on sched_spill_nr_run and sched_spill_load for
 how overcommitment threshold is defined and also notes on
 'sched_upmigrate_min_nice' tunable.
 
-*** 7.18 sched_static_cpu_pwr_cost
+*** 7.17 sched_static_cpu_pwr_cost
 
 Default value: 0
 
@@ -1218,7 +1208,7 @@ within a cluster and possibly have differing value between clusters as
 needed.
 
 
-*** 7.19 sched_static_cluster_pwr_cost
+*** 7.18 sched_static_cluster_pwr_cost
 
 Default value: 0
 
@@ -1229,7 +1219,7 @@ power mode. It ignores the actual D-state that a cluster may be in and assumes
 the worst case power cost of the highest D-state. It is means of biasing task
 placement away from idle clusters when necessary.
 
-*** 7.20 sched_early_detection_duration
+*** 7.19 sched_early_detection_duration
 
 Default value: 9500000
 
@@ -1240,7 +1230,7 @@ tick for it to be eligible for the scheduler's early detection feature
 under scheduler boost. For more information on the feature itself please
 refer to section 5.2.1.
 
-*** 7.21 sched_restrict_cluster_spill
+*** 7.20 sched_restrict_cluster_spill
 
 Default value: 0
 
@@ -1259,7 +1249,7 @@ CPU across all clusters. When this tunable is enabled, the RT tasks are
 restricted to the lowest possible power cluster.
 
 
-*** 7.22 sched_downmigrate
+*** 7.21 sched_downmigrate
 
 Appears at: /proc/sys/kernel/sched_downmigrate
 
@@ -1272,7 +1262,7 @@ its demand *in reference to the power-efficient cpu* drops less than 60%
 (sched_downmigrate).
 
 
-*** 7.23 sched_small_wakee_task_load
+*** 7.22 sched_small_wakee_task_load
 
 Appears at: /proc/sys/kernel/sched_small_wakee_task_load
 
@@ -1284,7 +1274,7 @@ categorized as small wakee tasks.  Scheduler places small wakee tasks on the
 waker's cluster.
 
 
-*** 7.24 sched_big_waker_task_load
+*** 7.23 sched_big_waker_task_load
 
 Appears at: /proc/sys/kernel/sched_big_waker_task_load
 
@@ -1443,7 +1433,6 @@ cpus are being reset. Changes to below attributes result in such a reset:
 * sched_window_stats_policy (See Sec 2.4)
 * sched_ravg_hist_size (See Sec 7.11)
 * sched_migration_fixup (See Sec 7.12)
-* sched_freq_account_wait_time (See Sec 7.11)
 
 <task>-0     [004] d.h4 12700.711489: sched_reset_all_windows_stats: time_taken 1123 window_start 0 window_size 0 reason POLICY_CHANGE old_val 0 new_val 1
 

include/linux/sched/sysctl.h

@@ -44,7 +44,6 @@ extern unsigned int sysctl_sched_wakeup_load_threshold;
 extern unsigned int sysctl_sched_window_stats_policy;
 extern unsigned int sysctl_sched_ravg_hist_size;
 extern unsigned int sysctl_sched_cpu_high_irqload;
-extern unsigned int sysctl_sched_freq_account_wait_time;
 extern unsigned int sysctl_sched_migration_fixup;
 extern unsigned int sysctl_sched_heavy_task_pct;
 extern unsigned int sysctl_sched_enable_power_aware;

kernel/sched/core.c

@@ -1764,7 +1764,7 @@ struct cpu_cycle {
 
 /*
  * sched_window_stats_policy, sched_ravg_hist_size,
- * sched_migration_fixup, sched_freq_account_wait_time have a 'sysctl' copy
+ * sched_migration_fixup have a 'sysctl' copy
  * associated with them. This is required for atomic update of those variables
  * when being modifed via sysctl interface.
  *
@@ -1799,8 +1799,7 @@ __read_mostly unsigned int sysctl_sched_new_task_windows = 5;
 static __read_mostly unsigned int sched_migration_fixup = 1;
 __read_mostly unsigned int sysctl_sched_migration_fixup = 1;
 
-static __read_mostly unsigned int sched_freq_account_wait_time;
+#define SCHED_FREQ_ACCOUNT_WAIT_TIME 0
-__read_mostly unsigned int sysctl_sched_freq_account_wait_time;
 
 /*
  * For increase, send notification if
@@ -2166,11 +2165,11 @@ static int account_busy_for_cpu_time(struct rq *rq, struct task_struct *p,
 		if (rq->curr == p)
 			return 1;
 
-		return p->on_rq ? sched_freq_account_wait_time : 0;
+		return p->on_rq ? SCHED_FREQ_ACCOUNT_WAIT_TIME : 0;
 	}
 
 	/* TASK_MIGRATE, PICK_NEXT_TASK left */
-	return sched_freq_account_wait_time;
+	return SCHED_FREQ_ACCOUNT_WAIT_TIME;
 }
 
 static inline int
@@ -2391,7 +2390,7 @@ void update_task_pred_demand(struct rq *rq, struct task_struct *p, int event)
 		return;
 
 	if (event != PUT_PREV_TASK && event != TASK_UPDATE &&
-			(!sched_freq_account_wait_time ||
+			(!SCHED_FREQ_ACCOUNT_WAIT_TIME ||
 			 (event != TASK_MIGRATE &&
 			 event != PICK_NEXT_TASK)))
 		return;
@@ -2401,7 +2400,7 @@ void update_task_pred_demand(struct rq *rq, struct task_struct *p, int event)
 	 * related groups
 	 */
 	if (event == TASK_UPDATE) {
-		if (!p->on_rq && !sched_freq_account_wait_time)
+		if (!p->on_rq && !SCHED_FREQ_ACCOUNT_WAIT_TIME)
 			return;
 	}
 
@@ -3186,7 +3185,6 @@ enum reset_reason_code {
 	POLICY_CHANGE,
 	HIST_SIZE_CHANGE,
 	MIGRATION_FIXUP_CHANGE,
-	FREQ_ACCOUNT_WAIT_TIME_CHANGE,
 	FREQ_AGGREGATE_CHANGE,
 };
 
@@ -3195,7 +3193,7 @@ const char *sched_window_reset_reasons[] = {
 	"POLICY_CHANGE",
 	"HIST_SIZE_CHANGE",
 	"MIGRATION_FIXUP_CHANGE",
-	"FREQ_ACCOUNT_WAIT_TIME_CHANGE"};
+};
 
 /* Called with IRQs enabled */
 void reset_all_window_stats(u64 window_start, unsigned int window_size)
@@ -3269,13 +3267,6 @@ void reset_all_window_stats(u64 window_start, unsigned int window_size)
 		old = sched_migration_fixup;
 		new = sysctl_sched_migration_fixup;
 		sched_migration_fixup = sysctl_sched_migration_fixup;
-	} else if (sched_freq_account_wait_time !=
-					sysctl_sched_freq_account_wait_time) {
-		reason = FREQ_ACCOUNT_WAIT_TIME_CHANGE;
-		old = sched_freq_account_wait_time;
-		new = sysctl_sched_freq_account_wait_time;
-		sched_freq_account_wait_time =
-				 sysctl_sched_freq_account_wait_time;
 	} else if (sched_freq_aggregate !=
 					sysctl_sched_freq_aggregate) {
 		reason = FREQ_AGGREGATE_CHANGE;

kernel/sched/fair.c

@@ -4055,9 +4055,6 @@ static inline int invalid_value_freq_input(unsigned int *data)
 	if (data == &sysctl_sched_migration_fixup)
 		return !(*data == 0 || *data == 1);
 
-	if (data == &sysctl_sched_freq_account_wait_time)
-		return !(*data == 0 || *data == 1);
-
 	if (data == &sysctl_sched_freq_aggregate)
 		return !(*data == 0 || *data == 1);
 

kernel/sysctl.c

@@ -323,13 +323,6 @@ static struct ctl_table kern_table[] = {
 		.mode           = 0644,
 		.proc_handler   = sched_window_update_handler,
 	},
-	{
-		.procname       = "sched_freq_account_wait_time",
-		.data           = &sysctl_sched_freq_account_wait_time,
-		.maxlen         = sizeof(unsigned int),
-		.mode           = 0644,
-		.proc_handler   = sched_window_update_handler,
-	},
 	{
 		.procname       = "sched_heavy_task",
 		.data           = &sysctl_sched_heavy_task_pct,