From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Zhou Ti (x2019cwm)" <x2019cwm@stfx.ca>
Subject: [PATCH v1 5/5] cpuidle: menu: Take negative "sleep length" values into account
Date: Mon, 29 Mar 2021 20:37:12 +0200 [thread overview]
Message-ID: <7927358.NyiUUSuA9g@kreacher> (raw)
In-Reply-To: <2764850.e9J7NaK4W3@kreacher>
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: [PATCH] cpuidle: menu: Take negative "sleep length" values into account
Make the menu governor check the tick_nohz_get_next_hrtimer()
return value so as to avoid dealing with negative "sleep length"
values and make it use that value directly when the tick is stopped.
While at it, rename local variable delta_next in menu_select() to
delta_tick which better reflects its purpose.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpuidle/governors/menu.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -271,7 +271,7 @@ static int menu_select(struct cpuidle_dr
u64 predicted_ns;
u64 interactivity_req;
unsigned long nr_iowaiters;
- ktime_t delta_next;
+ ktime_t delta, delta_tick;
int i, idx;
if (data->needs_update) {
@@ -280,7 +280,12 @@ static int menu_select(struct cpuidle_dr
}
/* determine the expected residency time, round up */
- data->next_timer_ns = tick_nohz_get_sleep_length(&delta_next);
+ delta = tick_nohz_get_sleep_length(&delta_tick);
+ if (unlikely(delta < 0)) {
+ delta = 0;
+ delta_tick = 0;
+ }
+ data->next_timer_ns = delta;
nr_iowaiters = nr_iowait_cpu(dev->cpu);
data->bucket = which_bucket(data->next_timer_ns, nr_iowaiters);
@@ -318,7 +323,7 @@ static int menu_select(struct cpuidle_dr
* state selection.
*/
if (predicted_ns < TICK_NSEC)
- predicted_ns = delta_next;
+ predicted_ns = data->next_timer_ns;
} else {
/*
* Use the performance multiplier and the user-configurable
@@ -377,7 +382,7 @@ static int menu_select(struct cpuidle_dr
* stuck in the shallow one for too long.
*/
if (drv->states[idx].target_residency_ns < TICK_NSEC &&
- s->target_residency_ns <= delta_next)
+ s->target_residency_ns <= delta_tick)
idx = i;
return idx;
@@ -399,7 +404,7 @@ static int menu_select(struct cpuidle_dr
predicted_ns < TICK_NSEC) && !tick_nohz_tick_stopped()) {
*stop_tick = false;
- if (idx > 0 && drv->states[idx].target_residency_ns > delta_next) {
+ if (idx > 0 && drv->states[idx].target_residency_ns > delta_tick) {
/*
* The tick is not going to be stopped and the target
* residency of the state to be returned is not within
@@ -411,7 +416,7 @@ static int menu_select(struct cpuidle_dr
continue;
idx = i;
- if (drv->states[i].target_residency_ns <= delta_next)
+ if (drv->states[i].target_residency_ns <= delta_tick)
break;
}
}
next prev parent reply other threads:[~2021-03-29 18:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-29 18:12 [PATCH v1 0/5] cpuidle: Take possible negative "sleep length" values into account Rafael J. Wysocki
2021-03-29 18:13 ` [PATCH v1 1/5] tick/nohz: Improve tick_nohz_get_next_hrtimer() kerneldoc Rafael J. Wysocki
2021-03-29 18:15 ` [PATCH v1 2/5] cpuidle: Use s64 as exit_latency_ns and target_residency_ns data type Rafael J. Wysocki
2021-03-29 18:19 ` [PATCH v1 3/5] cpuidle: teo: Adjust handling of very short idle times Rafael J. Wysocki
2021-03-29 18:21 ` [PATCH v1 4/5] cpuidle: teo: Take negative "sleep length" values into account Rafael J. Wysocki
2021-03-29 18:37 ` Rafael J. Wysocki [this message]
2021-03-30 1:59 ` [PATCH v1 5/5] cpuidle: menu: " Zhou Ti (x2019cwm)
2021-03-30 14:47 ` Rafael J. Wysocki
2021-04-07 17:24 ` [PATCH v1 0/5] cpuidle: Take possible " Rafael J. Wysocki
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