From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: [PATCH] cpuidle: menu: Replace data->predicted_us with local variable
Date: Mon, 01 Oct 2018 11:56:21 +0200 [thread overview]
Message-ID: <2889908.NE4FqvqlhV@aspire.rjw.lan> (raw)
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The predicted_us field in struct menu_device is only accessed in
menu_select(), so replace it with a local variable in that function.
With that, stop using expected_interval instead of predicted_us to
store the new predicted idle duration value if it is set to the
selected state's target residency which is quite confusing.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpuidle/governors/menu.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -124,7 +124,6 @@ struct menu_device {
int tick_wakeup;
unsigned int next_timer_us;
- unsigned int predicted_us;
unsigned int bucket;
unsigned int correction_factor[BUCKETS];
unsigned int intervals[INTERVALS];
@@ -290,6 +289,7 @@ static int menu_select(struct cpuidle_dr
int idx;
unsigned int interactivity_req;
unsigned int expected_interval;
+ unsigned int predicted_us;
unsigned long nr_iowaiters, cpu_load;
ktime_t delta_next;
@@ -315,7 +315,7 @@ static int menu_select(struct cpuidle_dr
* operands are 32 bits.
* Make sure to round up for half microseconds.
*/
- data->predicted_us = DIV_ROUND_CLOSEST_ULL((uint64_t)data->next_timer_us *
+ predicted_us = DIV_ROUND_CLOSEST_ULL((uint64_t)data->next_timer_us *
data->correction_factor[data->bucket],
RESOLUTION * DECAY);
@@ -341,7 +341,7 @@ static int menu_select(struct cpuidle_dr
/*
* Use the lowest expected idle interval to pick the idle state.
*/
- data->predicted_us = min(data->predicted_us, expected_interval);
+ predicted_us = min(predicted_us, expected_interval);
if (tick_nohz_tick_stopped()) {
/*
@@ -352,19 +352,18 @@ static int menu_select(struct cpuidle_dr
* the known time till the closest timer event for the idle
* state selection.
*/
- if (data->predicted_us < TICK_USEC)
- data->predicted_us = ktime_to_us(delta_next);
+ if (predicted_us < TICK_USEC)
+ predicted_us = ktime_to_us(delta_next);
} else {
/*
* Use the performance multiplier and the user-configurable
* latency_req to determine the maximum exit latency.
*/
- interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
+ interactivity_req = predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
if (latency_req > interactivity_req)
latency_req = interactivity_req;
}
- expected_interval = data->predicted_us;
/*
* Find the idle state with the lowest power while satisfying
* our constraints.
@@ -378,8 +377,8 @@ static int menu_select(struct cpuidle_dr
continue;
if (idx == -1)
idx = i; /* first enabled state */
- if (s->target_residency > data->predicted_us) {
- if (data->predicted_us < TICK_USEC)
+ if (s->target_residency > predicted_us) {
+ if (predicted_us < TICK_USEC)
break;
if (!tick_nohz_tick_stopped()) {
@@ -389,7 +388,7 @@ static int menu_select(struct cpuidle_dr
* tick in that case and let the governor run
* again in the next iteration of the loop.
*/
- expected_interval = drv->states[idx].target_residency;
+ predicted_us = drv->states[idx].target_residency;
break;
}
@@ -412,7 +411,7 @@ static int menu_select(struct cpuidle_dr
* expected idle duration so that the tick is retained
* as long as that target residency is low enough.
*/
- expected_interval = drv->states[idx].target_residency;
+ predicted_us = drv->states[idx].target_residency;
break;
}
idx = i;
@@ -426,7 +425,7 @@ static int menu_select(struct cpuidle_dr
* expected idle duration is shorter than the tick period length.
*/
if (((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) ||
- expected_interval < TICK_USEC) && !tick_nohz_tick_stopped()) {
+ predicted_us < TICK_USEC) && !tick_nohz_tick_stopped()) {
unsigned int delta_next_us = ktime_to_us(delta_next);
*stop_tick = false;
next reply other threads:[~2018-10-01 9:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-01 9:56 Rafael J. Wysocki [this message]
2018-10-01 14:46 ` [PATCH] cpuidle: menu: Replace data->predicted_us with local variable Daniel Lezcano
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